Started by HB9DNN, July 13, 2020, 05:32:38 PM
QuoteSpecification of TR-9 is in progress, and will be published before the end of this month.
QuoteI will think what You wrote about, but there are some things, that I can't change in this version. I'll write what I changed next day!
QuoteYou haven't noticed - there is a place(removed soldermask) for EM shielding - for PA, and RF chipset.
QuoteWe can even separate GND(avoid ground plane) for DCDC converter, which will be filtered using caps(GND-VCC) from two sides - input and output of converter. I think it can mitigate EMI.I think it's a good idea to second HW rev of TR-9.
QuoteThanks for your feedback! I had some connection problems and my previous post got lost. This is a concise version of it.1. Do that, publish it here. We can edit it later.
Quote2. We didn't perform any optimizations there, as this version is considered a Proof of Concept. Of course it has to be done later and we will certainly focus on that, when the time comes.
Quote3. 5V is used for the TFT and one op-amp in the RF section. The latter can be theoretically powered with 7.4V and the TFT can use a local (placed on the HMI board) DC-DC taking 7.4V input.
Quote4. LM386 is more than enough for this application. DB9MAT suggested, that shutting off this amp is not worth it. I'd focus on the mic section instead.
Quote5. U11 is for motion detection. Can be used for APRS and telemetry stuff. Good to have it.
Quote6. Why would we want to use RMII? UART is enough for sending some JSON queries and stuff like that.
Quote7. We could use async (USART) comm between hmi-mainboard and omit the XO, yeah.
Quote8. No QOS in half-duplex.
Quote from: undefined7. We could use async (USART) comm between hmi-mainboard and omit the XO, yeah.
Quote from: undefinedI assumed it is a one way UART interface. Except for high baud rates I guess the internal oscillator is accurate enough. Once more: experiments will show.