I’m having trouble using the Serial TTL function with the USB AVR Programmer. Could someone help me out?
System details: a Dell laptop running Windows 10 (migrated from Windows 7) with usbser.sys version 10.0.10586.71 (I’ve read the previous post on this forum about problems with Serial TTL on Windows 10 machines). I downloaded and installed the “USB AVR Programmer Windows Drivers and Software release 121114” from pololu.com/product/1300/resources before using the programmer.
Usage: I’m programming an ATmega168 using the AVR-GCC toolchain, AVRdude and Sublime Text 2 code editor, and have flashed the chip with a simple USART test which you can see here: github.com/hexagon5un/AVR-Progr … alLoopback.
Ports: The programmer is on COM4, and the Serial TTL port is on COM5. (The programmer works brilliantly by the way, and is much better than the USBasp that I used previously, much more reliable.)
Terminal: I’ve tried both Bray’s Terminal and PuTTY, both configured to use 9600 baud on COM5, and 8 bits, No parity, 1 stop bit (8N1).
Programmer/ TTL wiring: I’ve soldered a six-pin header into the contact holes for serial TTL/ Sloscope on the Pololu programmer. The flashed chip is on one breadboard, Pololu programmer in a separate breadboard. I have both the Pololu programmer wires and the TTL wires (VCC, GND, TX and RX) all connected to the appropriate pins on the Serial TTL header, ie TX header pin connects to the ATmega RX pin (pin 2) and vice versa. The AVR chip and programmer are running on the 5 volts from USB with no external power.
What happens: When I plug the programmer into a USB slot, the Pololu programmer gives me a yellow flashing light, so all looks good. Bray’s terminal gives me green indicators for CTS (Clear To Send), CD (Carrier Detect), DSR (Data Set Ready) and RI (Ring Indicator). I’ve also used a voltmeter to check continuity - I think there are good connections.
But I get no transmission from the chip. The code I’ve flashed the chip with should push a “Hello world” message via USART, then echo any text transmitted to the chip, but there’s nothing.
I’ve tried Adafruit’s FTDI Friend with the latest driver, and the same thing happens: no transmission. FTDI says it supports Windows 10, so surely this isn’t a Windows 10 problem. I must be doing something really, really daft, but I can’t see it! Help!