of course send various tones when changing the height of your sailplane.
- voice and tone
- use your own (wave-)samples in your language
- wave-samples stored on sd-card
- switch via rc between altitude-voice/vario-tone/off
- automatic announcement of altitude in hundred meter steps
- audio frequency output, you could use your own radios,PMR,FRS,baby monitor or whatever
- the Microcontroller will automatically switch on the radio and "press" the TX-button
- uses 5 Volt from rc-receiver
Here's my first Video, voice output is in german yet, but i 'll upload English voice-samples
Step 1: What You Need
- Parallax Propeller Microcontroller (-board)
i use cluso's CpuBlade because it is the smallest and lightest board
- (Micro-)SD Card + Socket
- Pressure Sensor Modul MS5611 on Breakoutboard
- some caps and resistors, see schematic
- you could use a stripboard or my layout for a PCB
- for the radio link:
i use a pair of PMR/FMR Walkie Talkie (15-20 $/Euro on Ebay)
up to 5 km Distance
- Programmer FTDI USB-TTL ( e.g. those needed for Arduino)
- wave-samples and firmware, see next steps
Step 2: PCB or Stripboard
When using my PCB here's a good making guide
Step 3: PCB
- PCB-Layout is a 1Bit-BMP
- Dimension: 51mm x 28mm
- best choice for SD-Socket is the micro-version, when using a "big" socket you have to assembly
with a little bit space between socket and pcb.
- solder pads for smd or wired caps and resistors, use bottom side for wired parts
- don't forget to connect the 3,3 V pad from sd-socket to 3,3 V regulator from the MS5611-board (see assembly/schematic)
Step 4: Programming the Vario and Prepare SD-card
You'll need the propeller tool.
After installing start the tool, connect the FTDI programmer to usb and pcb, open the binary i added
and load it into the Eeprom.
The Propeller Tool is very easy to use, the com-ports will automatically scanned for a connected propeller microcontroller.
Now it is time to prepare the SD-card with the wav-samples.
- Format the card with FAT.
- All samples must be placed in the root folder
- I added english spoken sound samples, see zip file
- You can download good samples from here or here
- 8 bit or 16 bit up to 44,1khz needed
- when using you own samples rename in 1.wav, 2.wav ........ (see zip file)
- SD-card max. size 2GB !!!
- When using the pcb with a normal sd-socket instead of micro-sd-socket you need another firmware because
another prop-pin for DI is used !
Step 5: Connecting Vario With Radio
There are five connections to be done:
- 5V supply voltage to the battery contact from radio, also ground
- remove the electret microphone from the radio and connect the "hot pin" to mic from vario
- hot pins from the power- and ptt-button (radio) to vario-pins power and ptt
(this is needed for automatically switch on the radio)
see also at the attached photo
Step 6: Final Details
- connect a free channel from you rc-receiver to the vario, use a fuse ( 0,5 A ) to avoid risk of shortcut,
the vario is powered by the rc-receiver !
- the rc-transmitter needs a 3-position switch:
Pos1 (off) : PropVario sends no information, radio-transmitter is off
Pos2(mid) : PropVario sends lower/higher tone when the plane is sinking/climbing
Pos3(on) : PropVario sends the actually altitude in meter
When powering the plane the vario turns on the radio and will welcome you with a spoken "ok".
Now you can test the vario-tone by raising the model in you hand.
Also the height response should be tested.
Maybe the rudder limits from your 3-position switch must be modified.
i think the hundret-meter-steps can only be tested in the air :-) they will automatically spoken every hundret meters
Checkout if the use of the radio/frequency is allowed in your country, this is only a test-example for the downlink.
I'll hope you enjoy and feel free to ask your questions !!!