Hey Dan,
Thanks for the clear explanation!
--David
On 09/13/2015 09:28 AM, Dan Smith wrote:
Ok, thanks for the confirmation on what Chirp does today. I am curious though if what Chirp downloads as an img from the radio is the complete radio image? If it is a complete image yet it only modifies the channel/freq/features areas, there still might be some hope that someday, a "very advanced" area could be added to flip these specific bits.
I think you're probably misunderstanding how these devices are laid out. Most of these single-chip radios are laid out with the following components:
A CPU, with some non-volatile firmware
An eeprom or flash memory array
The single-chip radio
firmware ^ |flash <-----> CPU <-----> radio | serial port | computer
The programming mode we have access to merely uploads and downloads ranges from #2. We don't get to access or change the firmware bit, and we certainly don't get to talk to the radio chip directly. The CPU could load some settings from the memory array and program the radio chip at startup, but I think it's unlikely. If it does, it would be pretty difficult to find this without some help or documentation. Regardless, it would be limited to whatever settings and values the firmware is designed to program the radio with. When we're in programming mode, we just have two commands: "write $blob to location $foo" and "read location $foo". The "image" we download is merely "every memory location from zero to end".
While I'm at it, I'm curious what people think about this specific 9600 baud hack that this HAM did. In an analog radio, one would need to tap into the discriminator to get a wide enough & flat pass band to support FSK over FM. Since these Baofeng radios are SDRs and pack everything into a few ASICs, I don't know if getting into this stage of the radio block is required anymore.
This is pretty off-topic for this list, so you should probably take it elsewhere.