Triggering a digital audio recorder on a Canon Zoom DS-8

[Jeremy Saint-Peyre]

Hello everybody !

Sorry for the silence, i was looking to put my hand on a multimeter to test the socket on the camera !

So, i know the socket work because i plugged a flash in and it worked :

So, to go further in this little project, i just had to mesure the electric power on the flash cord plugged in the socket according to Phil Rhodes, we need to know if it is a a short impulse or a continuous delivery. Here is the multimeter, i put it on 200V AC:


here is the cord :

It got me and absolute ZERO :


So i guess, my question is : What am i doing wrong ?

[Phil Rhodes]

It'll likely be connecting the pins of the socket together, as opposed to emitting a voltage.

[Jeremy Saint-Peyre]

15 hours ago, Phil Rhodes said:

It'll likely be connecting the pins of the socket together, as opposed to emitting a voltage.

Thanks, i am not sure i get what it means... The pins are connected mechanically at the moment i trigger the camera ?

[Andries Molenaar]

1 hour ago, Jeremy Saint-Peyre said:

Thanks, i am not sure i get what it means... The pins are connected mechanically at the moment i trigger the camera ?

The manual states that the connector can control a tape recorder. In that era it means it will short/connect the terminals when the camera runs. This would be connected to a remote control 2.5mm input of a recorder. On single frame it is fairly useless. ALthough the test flash demonstrates that the camera is working properly.

The trick is now to find a recorder which takes such a control or fix two wires inside a recorder or existing remote control with a button when pushed makes it record 🙂

 

Edited October 31, 2021 by Andries Molenaar

[Phil Rhodes]

1 hour ago, Jeremy Saint-Peyre said:

Thanks, i am not sure i get what it means... The pins are connected mechanically at the moment i trigger the camera ?

Well, yes, as Andries says, just connected together. That's what I'd expect.

Controlling the Zoom recorder is a little more complex. If I had one here I'd set up an Arduino to do it for you then it'd all be easy, but I don't.

P

[Jeremy Saint-Peyre]

21 minutes ago, Andries Molenaar said:

The manual states that the connector can control a tape recorder. In that era it means it will short/connect the terminals when the camera runs. This would be connected to a remote control 2.5mm input of a recorder. On single frame it is fairly useless. ALthough the test flash demonstrates that the camera is working properly.

The trick is now to find a recorder which takes such a control or fix two wires inside a recorder or existing remote control with a button when pushed makes it record 🙂

 

Thank you for your expertise ! My Zoom H4n do take remote control 2.5mm input, but i have doubt it'll work by plugin it in directly. Also i wanted to stop both recording simultaneously.

 

[Andries Molenaar]

Just now, Jeremy Saint-Peyre said:

Thank you for your expertise ! My Zoom H4n do take remote control 2.5mm input, but i have doubt it'll work by plugin it in directly. Also i wanted to stop both recording simultaneously.

 

INdeed, the physical apperance is less important 🙂  The cameras supplies a shorting switch. It connects the terminals when running. On classic taperecorders the remote was a switch in serial with the switches in the recorder.

 

[Jeremy Saint-Peyre]

6 minutes ago, Phil Rhodes said:

Well, yes, as Andries says, just connected together. That's what I'd expect.

Controlling the Zoom recorder is a little more complex. If I had one here I'd set up an Arduino to do it for you then it'd all be easy, but I don't.

P

Thank you, so if you both think it is still doable, i'm going to get in it. As i don't know where to start, wich arduino card should i use in your opinion ?

[Jeremy Saint-Peyre]

5 minutes ago, Andries Molenaar said:

INdeed, the physical apperance is less important 🙂  The cameras supplies a shorting switch. It connects the terminals when running. On classic taperecorders the remote was a switch in serial with the switches in the recorder.

 

That is foreign language to me 🤣

[Andries Molenaar]

5 minutes ago, Jeremy Saint-Peyre said:

That is foreign language to me 🤣

Clearly it is.  The camera shorts the terminals in the connecting point. Take it from there. Best were to find a Sony Walkman with recording opion or a MiniDisc recorder withproper input. Possibly a Digital recording thing wiht a simple iinput exits.
I would not start a project of constructing a digital apparatus using Arduine and what more. You will never win back the time and effort. 
simplest were to record just using a shart ahead, a clapper thing and stop after the scena was filmed.

Good luck.

 

Edited October 31, 2021 by Andries Molenaar

[Jeremy Saint-Peyre]

43 minutes ago, Andries Molenaar said:

Clearly it is.  The camera shorts the terminals in the connecting point. Take it from there. Best were to find a Sony Walkman with recording opion or a MiniDisc recorder withproper input. Possibly a Digital recording thing wiht a simple iinput exits.
I would not start a project of constructing a digital apparatus using Arduine and what more. You will never win back the time and effort. 
simplest were to record just using a shart ahead, a clapper thing and stop after the scena was filmed.

Good luck.

 

That would have been my choice if i wanted to shoot fiction, but i'm looking to shoot documentary, so i can't clap before/after a shoot in those conditions...

[Phil Rhodes]

5 hours ago, Jeremy Saint-Peyre said:

Thank you, so if you both think it is still doable, i'm going to get in it. As i don't know where to start, wich arduino card should i use in your opinion ?

Any of them, but for this I'd just get an Arduino Nano, or any of the clones of them. They're trivially inexpensive. You need a 3.3-volt version, not a 5-volt version, to talk to the Zoom recorder.

The thing is, just getting the board itself is only part of the story. You'd need to write some code to control the recorder, and if this is your first time it'll be a bit of a process. That might be OK if you didn't mind making a project out of it.

There's enough information available that I could try to do it remotely, but without being able to test with the real recorder it's tricky.

[Jeremy Saint-Peyre]

18 hours ago, Phil Rhodes said:

Any of them, but for this I'd just get an Arduino Nano, or any of the clones of them. They're trivially inexpensive. You need a 3.3-volt version, not a 5-volt version, to talk to the Zoom recorder.

The thing is, just getting the board itself is only part of the story. You'd need to write some code to control the recorder, and if this is your first time it'll be a bit of a process. That might be OK if you didn't mind making a project out of it.

There's enough information available that I could try to do it remotely, but without being able to test with the real recorder it's tricky.

Thank you for the informations ! So i guess this one will do the job :
https://www.distrelec.ch/en/arduino-nano-33-iot-arduino-abx00027/p/30150883?no-cache=true&marketingPopup=false&queryFromSuggest=true

I did some arduino based project... but i was more on the cutting/screwing/assembling parts side. I am aware of the code side, so i'll put my mind at it, and if you can help a bit i'll be thankfull !

I'm also sourcing materials and arduino for an other project, a telecinema based on Denis Carl (http://www.deniscarl.com/dokuwiki/doku.php?id=start) opensource telecinema and on a version done by a friend. So, i have no choice but to put myself into coding !

[Andries Molenaar]

Good luck, I hope it pays off. One day 🙂

 

[Phil Rhodes]

14 hours ago, Jeremy Saint-Peyre said:

if you can help a bit i'll be thankfull !

Happy to.

Bear in mind that everything I'm saying here is based on my theoretical, not practical, understanding of the camera and the recorder, so I could be wrong.

From my understanding this is how it works:

- Detect when the contacts on the camera close. I would buy an off-the-shelf flash port connector cable and cut it in half. Connect one side of the connector to the +3.3V power [actually, no, connect it to ground], and the other to an interrupt-capable GPIO pin. Configure the GPIO pin as an input with interrupts enabled [and the pullup set]. Write an appropriate interrupt-servicing routine. When the interrupt fires, you need to take some action.

- If the GPIO pin is currently set, start the camera, otherwise stop it. This will involve sending serial bytes to the recorder. The bytes you need to send are known from this open-source project. From what I can see there you need to send a "key down" code for the record button, then wait a few tens of milliseconds, then a "key up" code. Then, to stop, the key down code for the stop button, then wait, then the "key up" code. You may need to mess about with this a bit to make it behave as you want.

- The Arduino has a serial port. This is used for debug communications back to your computer, but you don't necessarily need that for this. I'd buy an off the shelf 2.5mm 4-pole jack cable, and cut it in half. Connect the Arduino serial output pin to the appropriate pin on the 2.5mm remote control port jack. The other pins on that jack will supply power and ground (you are running the Arduino from the Zoom recorder's power supply).

P

[aapo lettinen]

3 hours ago, Phil Rhodes said:

- Detect when the contacts on the camera close. I would buy an off-the-shelf flash port connector cable and cut it in half. Connect one side of the connector to the +3.3V power, and the other to an interrupt-capable GPIO pin. Configure the GPIO pin as an input with interrupts enabled. Write an appropriate interrupt-servicing routine. When the interrupt fires, you need to take some action.

in most cases it is safest to connect external switches to the power input by using a pullup resistor so that the whole system does not short circuit if there would be a problem with the external switch or cables/connectors. Additionally it is easier to arrange multiple remote switches this way because you only need one signal cable per switch and one single common ground wire, NOT two wires per switch.    So this way arranged it would be   3.3V input ---> pullup resistor from 2K to 20K depending on what you do ---> arduino pin input AND the outgoing wire to the switch  ----> the switch ----> ground.   When the switch is open the arduino pin is pulled to 3.3v by the pullup resistor and when the switch is closed the switch shorts the arduino pin to the ground and the pin reads 0v. The resistor limits the current so that nothing heats or uses too much current and capacitance is still successfully countered.

It might be useful to test with a oscilloscope if the switch needs a debounce capacitor to avoid multiple "switch pushes" when the camera is started and stopped (the arduino can detect every one of the bounces and may count from 3 to 10 "button pushes" per single mechanical operation of the switch. ) This may not be a problem if the Zoom recorder is not able to start and stop recording for millisecond long durations but it may still be worth checking out and can be corrected either by using a capacitor or in the arduino code if cap is not used

[aapo lettinen]

Just now, aapo lettinen said:

in most cases it is safest to connect external switches to the power input by using a pullup resistor so that the whole system does not short circuit if there would be a problem with the external switch or cables/connectors. Additionally it is easier to arrange multiple remote switches this way because you only need one signal cable per switch and one single common ground wire, NOT two wires per switch.    So this way arranged it would be   3.3V input ---> pullup resistor from 2K to 20K depending on what you do ---> arduino pin input AND the outgoing wire to the switch  ----> the switch ----> ground.   When the switch is open the arduino pin is pulled to 3.3v by the pullup resistor and when the switch is closed the switch shorts the arduino pin to the ground and the pin reads 0v. The resistor limits the current so that nothing heats or uses too much current and capacitance is still successfully countered.

additionally the arduino input pin would need a pulldown resistor if one would connect the power supply through the switch to the input pin... because when the switch is opened again there is enough capacitance in the circuit to leave the arduino input pin floating high for many seconds, maybe for minutes. One needs to pull it down to 0v intentionally to prevent it from floating, most commonly using a pulldown resistor (for example a 20K resistor between the pin and the ground) 

[Phil Rhodes]

I'd agree about putting something in series to limit current, but bear in mind the ATMEGA328 has internal pullups (set it as an input and then set it high as if it were an output). So, yes, do that, maybe, and pull the pin down.

[Phil Rhodes]

6 hours ago, aapo lettinen said:

It might be useful to test with a oscilloscope if the switch needs a debounce

This can probably be handled by ignoring switch events until the relevant key strokes have been sent to the recorder; the project I found had a 10ms delay between the key down and key up events, which should be adequate for debouncing.

[Jeremy Saint-Peyre]

Hello everyone !

I was on a trip but now i'm back at it. I will carefully read ad try to understand Phil and Aapo post. I've just ordered the Arduino Nano 33 IdO and an Arduino Uno kit !

[Helge Landgraf]

Hello,
I'm new to this forum, however I might be able to provide a proposal for a more simple solution.
Just attach a triggerable pulse mode frequency generator like this one to the camera's flash socket:
"PWM Impulse WSFG-06 20mA High Accuracy Signal Generator Multifunctional Adjustable Module for Pulse Mode" from Jeanoko (~30$).
It will generate a 1000Hz Impulse on every picture. Connect it's output to a free input of your digital audio recorder (if it has only 2 you'll have to sacrifice stereo sound for now).
Now set the output level of the little generator pretty high. Also set the trigger on your digital recorder for that input (if separately possible, if not also ok) pretty high and set it for automated recording, triggered by the input.

I have a Tascam DR40 with 4 channels, I sacrificed one of the additional microphone inputs for that.

Also I did set the pre-recording to 2 seconds, means that the digital recorder will always have 2 seconds of sound recorded before the actual trigger event, which avoids that upon starting the camera anything could be lost.

By using that generator and by using 1000Hz pulses (1 for ea picture) you are gaining a lot of benefits:

- You don not need to deal with any electronics that can actually mimic the protocol needed to trigger the real remote or any fooling with the record button or similar - you just do not need any of those neither do you need to start the recorder manually

- You are now compatible with a lot of sync appliances available for syncing sound and picture upon projection (in case you consider projection), like the Visacustic system

- Using an audio editing tool like Audacity allows you to cut your recording (eliminating the recorded areas between actual takes) and to evaluate the number of pictures vs time

I use the Tascam DR40 together with a Nizo S8 camera (Nizo Professional) that has already an output of one 1000Hz pulse per frame, and it works fine.

[Jeremy Saint-Peyre]

On 11/29/2021 at 6:25 PM, Helge Landgraf said:

Hello,
I'm new to this forum, however I might be able to provide a proposal for a more simple solution.
Just attach a triggerable pulse mode frequency generator like this one to the camera's flash socket:
"PWM Impulse WSFG-06 20mA High Accuracy Signal Generator Multifunctional Adjustable Module for Pulse Mode" from Jeanoko (~30$).
It will generate a 1000Hz Impulse on every picture. Connect it's output to a free input of your digital audio recorder (if it has only 2 you'll have to sacrifice stereo sound for now).
Now set the output level of the little generator pretty high. Also set the trigger on your digital recorder for that input (if separately possible, if not also ok) pretty high and set it for automated recording, triggered by the input.

I have a Tascam DR40 with 4 channels, I sacrificed one of the additional microphone inputs for that.

Also I did set the pre-recording to 2 seconds, means that the digital recorder will always have 2 seconds of sound recorded before the actual trigger event, which avoids that upon starting the camera anything could be lost.

By using that generator and by using 1000Hz pulses (1 for ea picture) you are gaining a lot of benefits:

- You don not need to deal with any electronics that can actually mimic the protocol needed to trigger the real remote or any fooling with the record button or similar - you just do not need any of those neither do you need to start the recorder manually

- You are now compatible with a lot of sync appliances available for syncing sound and picture upon projection (in case you consider projection), like the Visacustic system

- Using an audio editing tool like Audacity allows you to cut your recording (eliminating the recorded areas between actual takes) and to evaluate the number of pictures vs time

I use the Tascam DR40 together with a Nizo S8 camera (Nizo Professional) that has already an output of one 1000Hz pulse per frame, and it works fine.

Thank you Helge, i'm discovering your solution, i'll look into it ! Sorry for the late reaction...

[Helge Landgraf]

No problem!

There is no rush once you start talking about analogue film 😎

[christophernigel]

On 11/29/2021 at 6:25 PM, Helge Landgraf said:

Hello,
I'm new to this forum, however I might be able to provide a proposal for a more simple solution.
Just attach a triggerable pulse mode frequency generator like this one to the camera's flash socket:
"PWM Impulse WSFG-06 20mA High Accuracy Signal Generator Multifunctional Adjustable Module for Pulse Mode" from Jeanoko (~30$).
It will generate a 1000Hz Impulse on every picture. Connect it's output to a free input of your digital audio recorder (if it has only 2 you'll have to sacrifice stereo sound for now).
Now set the output level of the little generator pretty high. Also set the trigger on your digital recorder for that input (if separately possible, if not also ok) pretty high and set it for automated recording, triggered by the input.

I have a Tascam DR40 with 4 channels, I sacrificed one of the additional microphone inputs for that.

Also I did set the pre-recording to 2 seconds, means that the digital recorder will always have 2 seconds of sound recorded before the actual trigger event, which avoids that upon starting the camera anything could be lost.

By using that generator and by using 1000Hz pulses (1 for ea picture) you are gaining a lot of benefits:

- You don not need to deal with any electronics that can actually mimic the protocol needed to trigger the real remote or any fooling with the record button or similar - you just do not need any of those neither do you need to start the recorder manually

- You are now compatible with a lot of sync appliances available for syncing sound and picture upon projection (in case you consider projection), like the Visacustic system

- Using an audio editing tool like Audacity allows you to cut your recording (eliminating the recorded areas between actual takes) and to evaluate the number of pictures vs time

I use the Tascam DR40 together with a Nizo S8 camera (Nizo Professional) that has already an output of one 1000Hz pulse per frame, and it works fine.

Helge Landgraf / would be nice to see how you rigged the set up to camera ! any chance to post some photos or pm me please , Thank you christopher

[Jeremy Saint-Peyre]

On 11/29/2021 at 6:25 PM, Helge Landgraf said:

Hello,
I'm new to this forum, however I might be able to provide a proposal for a more simple solution.
Just attach a triggerable pulse mode frequency generator like this one to the camera's flash socket:
"PWM Impulse WSFG-06 20mA High Accuracy Signal Generator Multifunctional Adjustable Module for Pulse Mode" from Jeanoko (~30$).
It will generate a 1000Hz Impulse on every picture. Connect it's output to a free input of your digital audio recorder (if it has only 2 you'll have to sacrifice stereo sound for now).
Now set the output level of the little generator pretty high. Also set the trigger on your digital recorder for that input (if separately possible, if not also ok) pretty high and set it for automated recording, triggered by the input.

I have a Tascam DR40 with 4 channels, I sacrificed one of the additional microphone inputs for that.

Also I did set the pre-recording to 2 seconds, means that the digital recorder will always have 2 seconds of sound recorded before the actual trigger event, which avoids that upon starting the camera anything could be lost.

By using that generator and by using 1000Hz pulses (1 for ea picture) you are gaining a lot of benefits:

- You don not need to deal with any electronics that can actually mimic the protocol needed to trigger the real remote or any fooling with the record button or similar - you just do not need any of those neither do you need to start the recorder manually

- You are now compatible with a lot of sync appliances available for syncing sound and picture upon projection (in case you consider projection), like the Visacustic system

- Using an audio editing tool like Audacity allows you to cut your recording (eliminating the recorded areas between actual takes) and to evaluate the number of pictures vs time

I use the Tascam DR40 together with a Nizo S8 camera (Nizo Professional) that has already an output of one 1000Hz pulse per frame, and it works fine.

I'm back on my feet ! Thanks for the idea Helge, do you have any exemple that you shot with your Nizo and the PWM Impulse WSFG-06 i can look at ? I like how the idea is simple and elegant.

How does the pre-recording actually work ? Doesn't it make it hard to sync with the footage in post ?