RadioBoard is a small, standalone low-power capable board (under development!) with some uC and some radio transceiver.
There is again (still) interest in digital radio technology, loosely related to vems. A Hungarian guy (vfx.hu who is very skilled engineer, but not too convenient to speak English) received 100 CC2500 chips at 2005-08-19 that we have access to. So a radio link is as close as you like, if you want to read some datasheet and play with PCB design.
- Followup in [telemetry wiki]. Everything from this page should be moved there.
- new solutions from cypress: [WirelessUSB] is a recent find, worth to mention here too.
Standalone universal radio-modem
Spending time on a standalone radio modem would be more productive, there is a strong demand for short range radio modems that can replace a rs232 cable. Pretty much like what bluetooth can allready do, but could be done maybe just cheaper.
Simple Radio (modem point-2-point link) - not very flexible; but for just datalogging a racecar, it's often enough.
Possible ways to do it
- Bluetooth VemsFrontier/Bluetooth good for computer to vems connection. Replaces RS232 cable easily. Compatible with each others. Ezurio, formerly TDK, has nice reasonable priced (around 50euros/each) Bluetooth module, [see Elfa], build-in antenna upto 300m!
- Low-power RF-chips. Manufacturers like Nordic Semiconductor ASA, not really compatible to anything else than each others. 2.4GHz range maybe near to 10 meters, also 400/800MHz chips available with possibly longer range. Much like zigbees (I call them zigbees anyway).
- Zigbee chips. Manufacturer like Chipcon, are compatible with any manufacturers.
- If one want to sell radio devices, they need to be EMC tested. This is the case with the zigbees and as far as I know also with bluetooth even when using build modules like one from Ezurio. And this is not cheap at all! (maybe someone knows more about this?)
- wifi [V3OverTCPWireless]
Zigbee Applications
- Laptop connection thru RS232 or USB tranciever, with USB to RS232 chip wireless connection is just virtual serial port at computer. No changes to tuning programs, but only pure serial wire replace can be done easily with bluetooth also.
- Central locking system, [see OVO3], got one already, it's damn small. (this can't be done with bluetooth). Vems needs power all the time, so wired LCD and keyb power should be switched via FET/IGBT. Something else?
- Or could be used only for antitheft. If button no pressed car wont start or it could start but if MAP goes high car just stops, that would be nice. Or..
- Wireless LCD and some small keyboard or even PS2 keyb. Only problem is probably the batteries. How much does backlighted LCD draw? 5V * 20mA is reasonable, but backlight could be switched off. Recent PS2 use small (10..20mA) current. Feasible running on rechargable batteries.
Zigbee are great with small battery operated devices.
I have made a while ago proto HW with Nordic and old Atmel AT90S2313 uC. This chip does not have HW SPI so it's done by software and atmel-nordic works fine.
I think now that my goal is to make wireless zigbee link to replace the RS232 so all tuning softwares and terminal connection could be done thru it as now. But my personal goal after all is to make other wireless devices, I like to have central locking system and also wireless LCD&keyb, not just replace wire to the laptop just like what bluetooth can do. Then these wireless devices needs to be used like comm commands. It needs vems code extensions, but it makes it really really flexible!
OR zigbee could be also connected I2C or SPI at vems, no need to touch comm commands if it's bad-bad. But then zigbee link cannot be used universal radio modem to replace RS232 connection. Give your opinion!
This project has been low priority for too long. Bad news also for marketing RadioBoard, maybe it will be too expensive to approve own radio devices. But still my project is going on, slowly.
Today I tested zigbee communication range indoors and it worked pretty well thru 2 walls near 10 meters distance (couldn't get further indoors). This with small chip antenna. Now my next plan is making a manufactured pcb's after I got new Nordic nRF24L01 chips. 24L01 has many very nice features.
I still haven't really get to know vems software, I would like wirelessly to:
- Communicate VEMS with tuningprograms -> easy thru rs232 at VEMS side
- See and set engine parameters with PS2 keyboard and LCD
- How this should be done at VEMS side? If possible it would be nice if tuning program would work at the same time.
It would be easy just to build a rs232 over zigbee, but how complex sw modifications would vems need if PS2/lcd data goes thru rs232? There will be microcontroller at both zigbee side, but is only possible way to make this like MegaSquirts MegaView does (acting as tuning program to view data at lcd, right?).
See also