I recently purchased a package fo some cheap Arduino Nano development boards from Amazon. For a couple bucks more you get 5 instead of 3. The only downside is they have the CH340G serial chipset. In order to get these to program on the mac and avoid the stk500_getsync() errors a couple steps need to be followed:
- First download the latest serial driver for OSX from the vendors website here: Mac CH341 Serial Driver
- Follow the installation instructions in the readme.
- I had an old driver installed so I removed it first before installing the new driver and rebooting my machine
- Connect the serial cable and open the Arduino IDE
- In the IDE make sure you have the Arduino Nano selected and the appropriate com port
- This step is critical in the Tools menu select the Atmega328P (Old Bootloader) option.
- If you don’t to this you will still get stk500_getsync errors.
Hope this is helpful for someone having these issues.