I am working on solving a problem for a programming station for certain PCBA Modules.
I have to mount the PCBA on the Fixture. There are RX and TX, Gnd and Power Supply pogo pins locked to RX and TX test points on PCBA and the flash programming software runs on embedded PC. The communication from PC to Fixture is via COM Port. As PCBA's main microcontroller IC uses3V~0V levels, there is a small PCBA in the test fixture for converting the 3V~0V levels to standard +/-15 RS232 level for the controlling Embedded PC.
The flash programming has two stages. The fist stage is to load a S- Record program to the module with baud rate 9600. Then the second stage is to load the actual firmware at baud rate 115200.
What happens is that S-Record program loading is always successful in the first stage. Then when the actual firmware is loaded with baud rate 115200, the first few blocks are successfully loaded but it will fail in loading the third or fourth block.
Does any body has experience in it?
I don't know whether it is because of the test pins, power supply, serial cable, or the Embedded PCs.
Please give suggestions if possible.
Thanks and Best Regards