Best way to power OpenMV and the Pan & Tilt shield with a battery?

OpenMV Boards
1

I’m intersted in building a face tracking system that is battery powered. It will utilize the Pan & Tilt shield to control servos for positioning the camera.

While I understand the programming side well enough, I’m not as spun up on the hardward side, so am having troupble understanding the instructions on how to power the camera and servos using battery.

Can anyone provide an amazon link to the type of battery that could be used here? I’ve only worked with 3.7V LiPo batteries which had JST connections in past.

If I were to use a LiPo battery with a JST connection, would I instead have to strip off the connector and feed the wires into the unregulated battery voltage input connectors on the shield?

2

The OpenMV Cam can run off of the 3.7V LiPo. However, servos require 5-6V.

You’re going to want something like this: https://www.amazon.com/Tenergy-Rechargeable-Connector-Airplanes-Aircrafts/dp/B001BCOWLY/ref=sr_1_2_sspa?dchild=1&keywords=servo+battery&qid=1621962248&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExMTFVMjg3WkdMUzg5JmVuY3J5cHRlZElkPUEwNTY2NDMzMzNRTU5VT1ZDV1FRRCZlbmNyeXB0ZWRBZElkPUEwNDQ3NjQ1MkI0T1ExRzZGR1U1RCZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

3

Thanks for the info!

If using a battery such as the one you listed, would it be connected to the shield through the Servo BAT VCC & Ground pins highlighted here? :

pt-pinout
pt-pinout1920×1190 265 KB

If yes, then would this also power the camera as well, or does the camera need its own dedicated battery?

4

Yes, that will work.

5

For code to control the servos that are connected to the Pan & Tilt shield, is more similar to the code found in “Exmaples → OpenMV → Board Control → servo_control.py” or “Examples → OpenMV → Servo Shield → main.py”

It looks like each of them use a slightly different method, so I’m not sure which is better when connecting servos to the P&T shield

6

You have to control the servos using built in timers. This is not the servo shield with another I2C chip onboard.

7

So neither the ‘servo_control.py’ or ‘main.py’ files listed about would be an example of how to do this?

8

https://github.com/openmv/openmv/blob/master/scripts/examples/OpenMV/02-Board-Control/servo_control.py

9

The above is it. You just do servo and it drives the pins you want.