About
The CAN/RS232 Shield gives your OpenMV Cam the ability to transmit RS232 signals to equipment and communicate over the CAN bus at the same time! You can transmit data up to 1 Mb/s via RS232 and 8 Mb/s via CAN (this requires an OpenMV Cam with CAN-FD support, though otherwise, normal CAN maxes out at 1 Mb/s). RS232 uses P4 (TX) and P5 (RX). CAN uses P1 (TX) and P3 (RX). You may also move the TX channel for CAN to P2. Additionally, you can disconnect all of these pins if you don't need them.
Better yet! The shield features a wide voltage range 6-36V input, which is robust to reverse voltage and features robust transient surge protection. Use this input to power your OpenMV Cam from 12/24V power supplies without having to worry about damaging your camera. The wide range voltage supply outputs 5.4V on VIN via an OR'ing diode so that you can power your OpenMV Cam from multiple shields with OR'ing diodes (e.g. all of our dual header column shields).
The shield also features a robust 0-5V ADC input (AIN) that outputs 0-3.3V to your OpenMV Cam on P6. The input is robust to reverse voltage and features overvoltage protection (tested up to +/-36V). By shorting a solder bridge jumper on the board, which supplies a 240 ohm load on the input, you can work in 4-20mA mode. If you don't need the ADC input, you can disconnect it from P6, too.
Finally, the shield features a robust 0-5V digital input/output. The SYN pin is tolerant to reverse voltage (tested with -12V), shorting to ground, and shorting to 12V. By default, SYN acts as a digital input driving P10 in Open-Drain Mode so that you can support input triggering from multiple sources, all driving P10. Alternatively, you can switch SYN to be a digital output driving 0-5V for triggering devices from your OpenMV Cam instead of being triggered by them. So, whatever your use case is for triggering, the shield accommodates. If you don't need the trigger input/output, you can disconnect it from P10, too.
This shield is compatible with all OpenMV Cam models.
Applications
This shield is perfect for using your OpenMV Cam in a robotic application. You've got the wide voltage range power supply input to connect to a 12/24V power rail, and then CAN/RS232 to get on your robot's databus. Finally, thanks to onboard triggering support you can sync the camera up to an external event source.
Specs
- PWR (6V-36V) - Reverse Voltage Tolerant (up to -36V) - provides VIN with 5.4V - up to 600mA Draw
- 0-5V ADC Input with reverse voltage protection and built-in over-voltage clamping
- 0-5V Digital Input/Output support for camera syncing - built-in short circuit protection
- 8 Mb/s CAN-FD Interface - with filtering - terminated (can be disabled)
- 1 Mb/s RS232 Interface - with filtering
- All external interfaces have robust transient voltage protection
The external pin header is designed to grab 20-24 gauge solid core wire and not fail due to vibration. Once you hook up a circuit using this shield, you can be sure it will not come apart. Please use a flat head 1.0-2.0mm screwdriver to release the spring lock headers if you need to remove a wire.
If you want to use this shield with the stranded wire, we recommend using 22-24 gauge ferrules (here) crimped (here) to your wires before inserting them into the shield.
Power Consumption
- 2ma @ 3.3V from your OpenMV Cam's 3.3V rail
