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| -rw-r--r-- | doc/release-notes-1.0.xsl | 2 |
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diff --git a/doc/altusmetrum.xsl b/doc/altusmetrum.xsl index c778b1e1..aeb43acb 100644 --- a/doc/altusmetrum.xsl +++ b/doc/altusmetrum.xsl @@ -657,80 +657,6 @@ NAR #88757, TRA #12200 </para> </section> </section> - <section> - <title>Calibration</title> - <para> - There are only two calibrations required for a TeleMetrum board, and - only one for TeleDongle and TeleMini. - </para> - <section> - <title>Radio Frequency</title> - <para> - The radio frequency is synthesized from a clock based on the 48 MHz - crystal on the board. The actual frequency of this oscillator must be - measured to generate a calibration constant. While our GFSK modulation - bandwidth is wide enough to allow boards to communicate even when - their oscillators are not on exactly the same frequency, performance - is best when they are closely matched. - Radio frequency calibration requires a calibrated frequency counter. - Fortunately, once set, the variation in frequency due to aging and - temperature changes is small enough that re-calibration by customers - should generally not be required. - </para> - <para> - When the radio calibration value is changed, the radio - frequency value is reset to the same value, so you'll need - to recompute and reset the radio frequency value using the - new radio calibration value. - </para> - </section> - <section> - <title>TeleMetrum Accelerometer</title> - <para> - The TeleMetrum accelerometer we use has its own 5 volt power supply and - the output must be passed through a resistive voltage divider to match - the input of our 3.3 volt ADC. This means that unlike the barometric - sensor, the output of the acceleration sensor is not ratio-metric to - the ADC converter, and calibration is required. We also support the - use of any of several accelerometers from a Freescale family that - includes at least +/- 40g, 50g, 100g, and 200g parts. Using gravity, - a simple 2-point calibration yields acceptable results capturing both - the different sensitivities and ranges of the different accelerometer - parts and any variation in power supply voltages or resistor values - in the divider network. - </para> - <para> - To calibrate the acceleration sensor, use the 'c a 0' command. You - will be prompted to orient the board vertically with the UHF antenna - up and press a key, then to orient the board vertically with the - UHF antenna down and press a key. - As with all 'c' sub-commands, follow this with a 'c w' to write the - change to the parameter block in the on-board DataFlash chip. - </para> - <para> - The +1g and -1g calibration points are included in each telemetry - frame and are part of the header extracted by ao-dumplog after flight. - Note that we always store and return raw ADC samples for each - sensor... nothing is permanently "lost" or "damaged" if the - calibration is poor. - </para> - <para> - In the unlikely event an accel cal that goes badly, it is possible - that TeleMetrum may always come up in 'pad mode' and as such not be - listening to either the USB or radio link. If that happens, - there is a special hook in the firmware to force the board back - in to 'idle mode' so you can re-do the cal. To use this hook, you - just need to ground the SPI clock pin at power-on. This pin is - available as pin 2 on the 8-pin companion connector, and pin 1 is - ground. So either carefully install a fine-gauge wire jumper - between the two pins closest to the index hole end of the 8-pin - connector, or plug in the programming cable to the 8-pin connector - and use a small screwdriver or similar to short the two pins closest - to the index post on the 4-pin end of the programming cable, and - power up the board. It should come up in 'idle mode' (two beeps). - </para> - </section> - </section> </chapter> <chapter> @@ -1360,10 +1286,10 @@ NAR #88757, TRA #12200 <section> <title>Callsign</title> <para> - This value is used in command packet mode and is transmitted - in each packet sent from TeleDongle and received from - TeleMetrum. It is not used in telemetry mode as that transmits - packets only from TeleMetrum to TeleDongle. Configure this + This value is transmitted in each command packet sent from + TeleDongle and received from an altimeter. It is not used in + telemetry mode, as the callsign configured in the altimeter board + is included in all telemetry packets. Configure this with the AltosUI operators call sign as needed to comply with your local radio regulations. </para> @@ -2449,6 +2375,111 @@ NAR #88757, TRA #12200 once you enable the voice output! </para> </appendix> + <appendix> + <title>Calibration</title> + <para> + There are only two calibrations required for a TeleMetrum board, and + only one for TeleDongle and TeleMini. All boards are shipped from + the factory pre-calibrated, but the procedures are documented here + in case they are ever needed. Re-calibration is not supported by + AltosUI, you must connect to the board with a serial terminal program + and interact directly with the on-board command interpreter to effect + calibration. + </para> + <section> + <title>Radio Frequency</title> + <para> + The radio frequency is synthesized from a clock based on the 48 MHz + crystal on the board. The actual frequency of this oscillator + must be measured to generate a calibration constant. While our + GFSK modulation + bandwidth is wide enough to allow boards to communicate even when + their oscillators are not on exactly the same frequency, performance + is best when they are closely matched. + Radio frequency calibration requires a calibrated frequency counter. + Fortunately, once set, the variation in frequency due to aging and + temperature changes is small enough that re-calibration by customers + should generally not be required. + </para> + <para> + To calibrate the radio frequency, connect the UHF antenna port to a + frequency counter, set the board to 434.550MHz, and use the 'C' + command in the on-board command interpreter to generate a CW + carrier. For TeleMetrum, this is best done over USB. For TeleMini, + note that the only way to escape the 'C' command is via power cycle + since the board will no longer be listening for commands once it + starts generating a CW carrier. + </para> + <para> + Wait for the transmitter temperature to stabilize and the frequency + to settle down. Then, divide 434.550 MHz by the + measured frequency and multiply by the current radio cal value show + in the 'c s' command. For an unprogrammed board, the default value + is 1186611. Take the resulting integer and program it using the 'c f' + command. Testing with the 'C' command again should show a carrier + within a few tens of Hertz of the intended frequency. + As with all 'c' sub-commands, follow this with a 'c w' to write the + change to the parameter block in the on-board DataFlash chip. + </para> + <para> + Note that any time you re-do the radio frequency calibration, the + radio frequency is reset to the default 434.550 Mhz. If you want + to use another frequency, you will have to set that again after + calibration is completed. + </para> + </section> + <section> + <title>TeleMetrum Accelerometer</title> + <para> + The TeleMetrum accelerometer we use has its own 5 volt power + supply and + the output must be passed through a resistive voltage divider to match + the input of our 3.3 volt ADC. This means that unlike the barometric + sensor, the output of the acceleration sensor is not ratio-metric to + the ADC converter, and calibration is required. Explicitly + calibrating the accelerometers also allows us to load any device + from a Freescale family that includes at least +/- 40g, 50g, 100g, + and 200g parts. Using gravity, + a simple 2-point calibration yields acceptable results capturing both + the different sensitivities and ranges of the different accelerometer + parts and any variation in power supply voltages or resistor values + in the divider network. + </para> + <para> + To calibrate the acceleration sensor, use the 'c a 0' command. You + will be prompted to orient the board vertically with the UHF antenna + up and press a key, then to orient the board vertically with the + UHF antenna down and press a key. Note that the accuracy of this + calibration depends primarily on how perfectly vertical and still + the board is held during the cal process. As with all 'c' + sub-commands, follow this with a 'c w' to write the + change to the parameter block in the on-board DataFlash chip. + </para> + <para> + The +1g and -1g calibration points are included in each telemetry + frame and are part of the header stored in onboard flash to be + downloaded after flight. We always store and return raw ADC + samples for each sensor... so nothing is permanently "lost" or + "damaged" if the calibration is poor. + </para> + <para> + In the unlikely event an accel cal goes badly, it is possible + that TeleMetrum may always come up in 'pad mode' and as such not be + listening to either the USB or radio link. If that happens, + there is a special hook in the firmware to force the board back + in to 'idle mode' so you can re-do the cal. To use this hook, you + just need to ground the SPI clock pin at power-on. This pin is + available as pin 2 on the 8-pin companion connector, and pin 1 is + ground. So either carefully install a fine-gauge wire jumper + between the two pins closest to the index hole end of the 8-pin + connector, or plug in the programming cable to the 8-pin connector + and use a small screwdriver or similar to short the two pins closest + to the index post on the 4-pin end of the programming cable, and + power up the board. It should come up in 'idle mode' (two beeps), + allowing a re-cal. + </para> + </section> + </appendix> <appendix xmlns:xi="http://www.w3.org/2001/XInclude"> <title>Release Notes</title> diff --git a/doc/release-notes-1.0.xsl b/doc/release-notes-1.0.xsl index a3fc22d9..1a06a43d 100644 --- a/doc/release-notes-1.0.xsl +++ b/doc/release-notes-1.0.xsl @@ -30,7 +30,7 @@ just isn't possible, or where radio transmissions might cause trouble with other electronics, there's a configuration option to disable all telemetry. Note that the board will still - enable packet mode in idle mode. + enable the radio link in idle mode. </listitem> <listitem> Arbitrary frequency selection. The radios in Altus Metrum |