Search found 44 matches

by turboscrew
Thu Aug 10, 2017 7:29 pm
Forum: Off topic
Topic: USB-to-TTL
Replies: 2
Views: 255

Re: USB-to-TTL

Thanks! Not all the data sheet versions seem to have mentioned the internal regulator current, but this has: http://www.usconverters.com/downloads/datasheets/pl2303.pdf Page 15. And there someone has done some research. Note that he doesn't say the chip survives the 400 mA. :lol: http://nerdralph.bl...
by turboscrew
Thu Aug 10, 2017 2:14 pm
Forum: Off topic
Topic: USB-to-TTL
Replies: 2
Views: 255

USB-to-TTL

I bought some of these lately (well, different seller, but YP-01 on the bottom anyway). https://www.aliexpress.com/item/PL2303-USB-To-RS232-TTL-Converter-Adapter-Module/32643748009.html?spm=2114.search0305.4.57.OiruJX It says "500mA self recovery fuse for protection". Which overcurrent? I didn't see...
by turboscrew
Fri Jul 28, 2017 8:09 pm
Forum: Off topic
Topic: What is RSSI
Replies: 10
Views: 482

Re: What is RSSI

Thanks, Pito. Very enlightening. As such I think it doesn't matter whether it's energy or something somehow dependent of the energy... I don't, however, understand, how the time domain fits here. Is it because of the way digital filters work (basically difference equations)? I'd consider filters mor...
by turboscrew
Fri Jul 28, 2017 6:14 pm
Forum: Off topic
Topic: What is RSSI
Replies: 10
Views: 482

Re: What is RSSI

I was wondering... If RSSI gives a measure of energy within a band, then widening the receive filter should produce higher RSSI, because the band now contains the same energy as before, but also energy from background noise that didn't fit within the narrower band. So would it work if I divided the ...
by turboscrew
Fri Jul 28, 2017 5:45 pm
Forum: Off topic
Topic: Learning about 433 MHz radios - how?
Replies: 23
Views: 1389

Re: Learning about 433 MHz radios - how?

Hmm. RSSI is till somewhat unclear - especially comparison between two bands of different widths... But if someone else is in the situation I was when I started this thread, the probably most important things are these: 0.5 <= 2*Fdev/BR <= 10 // modulation depth Bitrate < 2*RXBW // oversampling rule...
by turboscrew
Fri Jul 28, 2017 3:13 pm
Forum: Off topic
Topic: Has anyone programmed Si4432 or similar chip?
Replies: 2
Views: 178

Re: Has anyone programmed Si4432 or similar chip?

I didn't seem to be able to find any radio HW sources in the openLRSng github repo. :oops:
by turboscrew
Thu Jul 27, 2017 11:50 pm
Forum: Off topic
Topic: Has anyone programmed Si4432 or similar chip?
Replies: 2
Views: 178

Has anyone programmed Si4432 or similar chip?

I wonder if someone knows about those chips or knows where to find more info about them. There are the data sheets, the register description and demo code, but those don't exactly tell much about programming the chip. Like in the demo code, there is: /*enable receiver chain*/ SpiWriteRegister(0x07, ...
by turboscrew
Thu Jul 27, 2017 1:24 pm
Forum: STM32F103 Boards
Topic: Blue pill current?
Replies: 7
Views: 494

Re: Blue pill current?

I don't know which schematics to look into.. BPill http://wiki.stm32duino.com/images/c/c1/Vcc-gnd.com-STM32F103C8-schematic.pdf I understand that different manufacturers can use different components. A friend of mine has some bluepills with totally wrong RTC crystals. On his boards, the RTC doesn't...
by turboscrew
Thu Jul 27, 2017 10:39 am
Forum: STM32F103 Boards
Topic: Blue pill current?
Replies: 7
Views: 494

Re: Blue pill current?

I don't know which schematics to look into - there is no sign of any manufacturer. I took a microscope shot from the chip, though, and it says "DE=A1D" on the top. I guess it's RT9193-33GB. Thanks a heap!

I guess it's better NOT to use the on-board internal regulator.
by turboscrew
Thu Jul 27, 2017 9:38 am
Forum: Off topic
Topic: What is RSSI
Replies: 10
Views: 482

Re: What is RSSI

Yep, but they don't explain the RSSI mesurement: what is measured an how. What I'm wondering is that very often when I get some data, the RSSI is pretty small. I get better RSSI with smaller RX filter bandwidth, but no data. What I'd like to know, if there is the same transmission that fits within t...