AMSAT-DL: Homepage
AMSAT-DL: Github
Hardware, Kits:
Software:
Tips and Tricks:
Downloads:
QO100 Downconverter Firmware
QO100 Upconverter Firmware
QO100 GPS V2 Module Firmware
QO100 HS Modem Source
QO100 HS Modem Images
The Amsat-Uponverter Version-4.2 has a serial interface on a 6-pin plug connector near the LED row. Diagnostic messages and measured values are output here:
Level: 3.3 volts (for connection to an RS232 interface a 3.3V - RS232 converter is ABSOLUTELY required!) Baud rate: 9600 Bd Data bits: 8 Stop bits: 1 Parity: none
The diagnostic messages are of no interest to normal users.
But what is particularly interesting is the output of measurement data:
UPC_AA_BB_text completed with newline.
It means:
UPC … 3 character header to indicate that display content follows. Lines that do not begin with UPC can be ignored.
_ … spaces
AA … always twice 0, i.e. 00
_ … spaces
BB … ID of the following data record
_ … spaces
text … data content as ASCII text
Here is a selection of information that is output:
| BB | Description |
| 00 | PA temperature in degC |
| 01 | internal supply voltage after the 5V step-down converter in mV |
| 02 | a voltage that corresponds to the transmission power (forward power) followed by the dBm value (approximate value) |
| 04 | Status of the LOCK LED |
| 05 | Frequency of the mixer oscillator |
| 06 | Status of the PTT LED or the PTT input |
| 07 | Welcome message after switching on |
| 08 | Message when the synthesizer resynchronizes, e.g. after failure of an external reference frequency |
| 09 | LOCK status of the ADF4531 synthesizer |
| 10 | Input frequency of the upconverter, corresponding to jumpers M, N |
| 11 | Overtemperature alarm: ON or OFF (threshold: 75 degrees C) followed by temperature in degC |
| 12 | Undervoltage alarm (5V step-down converter): voltage in mV |
| 13 | Overvoltage alarm (5V step-down converter): voltage in mV |
The Amsat-DL downconverter also has corresponding serial messages. In order to be able to receive both with a single serial interface, downconverter and upconverter can be connected in series:
The serial output of the downconverter is connected to the serial input of the upconverter. The serial output of the upconverter is connected to a computer via a 3.3V RS232 level converter. All messages can then be read on the computer. The messages of the downconverter begin with the header “OLD”, those of the upconverter with “UPC”. See also HERE.
The performance is measured with an AD8312. The AD8312 is a logarithmic power detector. Its output voltage corresponds to the power in dBm.
If you want to measure the actual performance, a comparison must first be made. This means that the relationship between the measured output voltage and real power must be measured for two powers (one low and one high). Then you can convert each measured voltage into the associated power. It is not yet known whether this comparison has to be carried out for each individual circuit board or whether it can be made generally valid, because a larger number of circuit boards is required for this. If you need exact results, you have to carry out the comparison for the individual circuit board.
The evaluation of several boards showed that the measured values are very similar, so that a dBm accurate measurement should be possible. The above message UPC 00 02 outputs both the measurement voltage of the AD8312 and the estimated power in dBm. At the moment this “estimate” looks very precise, whether it stays that way will be seen after the production of a large number of circuit boards.
