Alternatively, you can use an RS-232 to TTL level converter, such as Arduino RS232 to TTL Converter with DB9 (MAX202) - DFRobot (cheaper can be found) and connect to your PC’s COM port, if you have one, using a serial cable. I’ve used both Brett’s recommended method and the RS-232 method with great success. The converter is important, as the Panda runs 0V-5V and RS-232 out of your PC runs -12V to 12V.
Incidentally, I am currently using a TTL to convert to RS-232 and then using a dongle to convert the RS-232 to virtual com over USB. Why? Because I have COM1 all wired up for RS-232 on the Panda II, but no available COM ports on this new dev machine.
Ok, so this is what I did. I only had a Serial to UART converter, so from COM1 I ran it into the UART-Serial then the serial line into my RS232-USB converter (since I dont have a RS232 port on my computer.
I have the Mod pin jumped to ground. But I am not getting a response from the device?
You should start by this, keep on using USB for debugging like you always do. Add your TTL to USB converter to COM1 and then open COM1 on code and send data. Make sure this data is actually sent. A terminal software is what you need, like teraterm.
Once that is working and you can send and receive data from terminal, now connect MOD low and try to deploy from serial.
You may be able to use the UART to Serial and Serial to USB together. See my picture in the post above. I have a UART to Serial converter on the stackable shield connected to the Panda, then a Serial To USB converter (the blue plug) going to a USB cable extender and back to the PC USB port.
As for mass storage, I agree with Gus. Get the debugging over COM1 working first, it will make your coding so much easier in the long run. Don’t give up, you are actually quite close to your goal.
Ok, So I think I have everything setup correct. I am debugging over USB and trying to send data out of the COM1. I followed the UART-PC tutorial using the below code, and I am not seeing anything in my TeraTerm connection. The code bulds successfully, however when I debug, at the end of the output window I see Error: a3000000
public class Program
public static void Main()
SerialPort UART = new SerialPort("COM1", 115200);
// create a string
string counter_string = "Count: " + counter.ToString() +
// convert the string to bytes
byte buffer = Encoding.UTF8.GetBytes(counter_string);
// send the bytes on the serial port
UART.Write(buffer, 0, buffer.Length);
// increment the counter;