forum.pistar.uk

This has been bugging me. The 1.3 screen works fine, the 0.96 does not. Here's what's going on. The 1.3" screen uses the SSD1306 controller. Adafruit uses this controller on all their OLED screens. The (cheap) Chineese OLED screens use an older SSD1106 controller. Raspberry Pi uses the Adafruit...

The receivers are total garbage. They also make great mixers. I solve most of my problems by placing a 6-10 dB attenuator between the hotspot and the antenna. You can find SMA attenuators that will work well. The DV4mini placed a 6 dB attenuator on the PCB, which is the right thing to do. I have yet...

It's not as simple as changing the frequency. In going from the 440 MHz to the 960 MHz bands, the 7021 needs to be configured differently in order to achieve optimal VCO/PLL performance. I don't believe the MMDVM firmware considers frequency when setting these parameters thus as you move out of the ...

On a ZumSpot purchased from HRO with the Pi Zero W, I noticed that the 3V3 and 5V Power (pins 1 and 2) are shorted together! Huh? A DVM measurement shows that the ZumSpot board is getting 5V and the 3V3 line on the PiZW is 5V. Shorting pins 1&2 shorts the input of the 3V3 regulator to the output...

Thank-you for taking the time to respond. It is a bit confusing how all of this works and which bits are Pistar and so on. I looked through the Pistar website and couldn't find anything related to a development respository. So posted here. Unfortunately most people will associate the Pistar brand wi...

To use the AD7021 transceiver on VHF it is necessary to use the external inductor VCO. (The internal inductor VCO is only good for 420 MHz and higher.) This requires the board to actually have this inductor which should be between pins 44 and 46. In addition the firmware must actually select the use...

The AD7021 transceiver chip used in the Zumspot requires that the IF be calibrated. The IF is an analog on-chip system that is temperature sensitive and must be calibrated to perform well. Analog Devices requires that an IF calibration be performed whenever the 7021 enters receive mode. In addition,...

The issue here is that the 7021 appears to be managed in such a way that frequency is extremely critical. I would think you'd want your hotspot to work better. Your suggestion would not work. Garbage generated by the hotspot would still be garbage when it hit WiRES-X. Your comment is off-topic as th...

The BER using YSF on a ZumSpot is extremely sensitive to frequency. Changing RXOffset by a few hundred Hz can make the difference between low BER and very high BER (or no Rx) on Rx. The DV4mini uses the same ADI7021 chip and is very insensitive to frequency error. It is possible to vary the frequenc...