Hopefully I have posted in the correct area. I am having issues with a DIY Arduino PCB that I have created, have spent some weeks trying to find a solution and also tinkering with different connections/components to get this to work, no luck so far.
I am new to using Arduino and am learning the programming language but would have a lot of experience with building PCBs using PIC and PICAXE microcontrollers.
I have attached the PCB diagram along with the soldered PCB. The design is based on a schematic from Arduino Workshop PDF.
The PCB itself does seem to work, the main issue is using the FTDI cable to download a sketch. I have downloaded the blink sketch to an existing Arduino Uno, removed the ATMEGA328P from the Uno and placed in my PCB and I am able to get the LEDs to light, so I am confident the general circuit works.
I have tried using Arduino IDE and also used the new Arduino Web Editor, same result that it can't download to the PCB. I have changed the settings for the Duemilanove with 328P. The FTDI cable is the 5V model the same as this link:
The ATMEGA328P has the built in bootloader, and as I said I am able to download the blink sketch through the Uno, so my issue is around the FTDI cable area. From my research into this problem I think the issue is around the reset area of the PCB and I am hoping someone here can spot my problem.
Unsoldered connections on the PCB are for inputs and outputs not needed at this moment until I can get the PCB fully working with the LEDs.
Also the empty terminal blocks in series with the RX/TX/5V/0V were for a RFID reader.
Cant really help but a couple of maybe obvious pointers;
if you program with the FTDI you will overwrite the bootloader, so then you cannot then load a program by any other means ( other serial port, USB) , unless you replace the bootloader. You can upload the bootloader using the FDTI board.
If using another Arduino to program, have you put the capaictor in place that pulls down the reset line just after compiling and start of upload? I did have a problem in this area with a microview and was told to put a pull up resisitor on the reset line ( iy made no difference , but worth a try)
In order to get autoreset to work so you can easily program it, you need to have DTR connected to reset through a capacitor. One side of that cap connected to DTR needs to go to the reset pin, the other side to DTR of FTDI adapter. It looks like you have the other side of the cap connected to Vcc instead of reset.
spycatcher2k and DrAzzy I have had a look at the DTR/RTS (same thing yeah?) during my online research and realised there was an issue there, on the schematic I followed the RTS was connected to the VCC with a 100nF cap but I broke the tracks leading to the VCC and placed a jump wire to the connection between the 10k pull up resistor and the tactile reset switch. Still had no luck with the download (assuming I connected it right).
I also tried changing the 10K pull up resistor to a 1K as I had read that somewhere as well but still no luck.
Issue has to be around the reset area.
PaulHammy does a 328P IC with boot loader installed not work with FTDI, I do have some 328P ICs with no boot loader I can try? I wouldn't be sure though how to burn the boot loader on, another FTDI board is needed for burning boot loader?
No luck this afternoon, ended up breadboarding it to speed things up. No use.
I'd imagine it has to be the cable?
Ended up ordering a FTDI 5V Basic Breakout from Sparkfun, should arrive before end of week and will
try it with breadboard. Will know for certain then.
SM
if you program with the FTDI you will overwrite the bootloader, so then you cannot then load a program by any other means ( other serial port, USB) , unless you replace the bootloader. You can upload the bootloader using the FDTI board.
This is completely wrong. FTDI boards are just a USB->UART converter, they are not an ISP.
