When you start developing a GPS solution, you have to deal with energy and for this you have to create a strategy based on what you expect and the size of your battery.
Basically, a GPS is consuming about 25mA when running. An active antenna will consume about 10mA more. The first time you start it, it have to sync with the satellites, get the ephemeris then you can position in 2D then in 3D.
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Telecom Design TD1204 have really limited number of GPIOs available even if it have many pins 🙁 … So you quickly have to use the DB2-DB3 pin that are usually used by SWD port.
If you try to reconfigure directly the Pin, this will not work until you inactivate SWD. For this, you must call first the following functions :
GPIO_DbgSWDIOEnable(false); GPIO_DbgSWDClkEnable(false);
…
A good way to expand Telecom Design system is to use I2C to connect external devices. As an example I had to add an extra Analog to Digital converter. I’m using a MCP3021Ax device. This I2C chip just return a 10bits value each time you send a READ at the expected address. This post contains the TD1204 code to configure I2C and get the data back
TD1204 / Sigfox & GPS
Telecom Design provides 4 different chips to support SigFox communications. This post details the differences of each of them in term of functionnalities
All are modules are based on a EFM32 / Cortex M3 micro-controler with 128KB flash, 16KB RAM, ultra low power including a Silicon Labs transceiver. The chip is a EFM32G210F128
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This is not my lab !
I’m starting a project with a couple of friends and today they ask me : “if we want to duplicate your lab to parallelize the hardware stuff, what to we need?” That was an interesting question I want to share in this post. So I’m going to list all the stuff I’m using frequently with its price for my home hacking.
All that stuff is low end material but affordable !
ATtiny45 and ATtiny85 are small Atmel micro-controleur like the 328p with less legs and smaller price. They can be nice platform for really small system does not requiring a lot of I/Os.
You can install Arduino on this device really easily. I won’t describe how to do because this excellent tutorial contains all what we need.
Ixys solar panel
I’m looking at solar energy to power IoT device that will be used in a car. I did not found a lot of documentation on what we can do with solar panel and what kind of energy we can expect to get with a such system.
This post will summarize the information I got on solar panels and measures done.
Telecom Design LAN capability is a 9600bps rf 868 transmission you can use with the sigfox modem to communicate between multiple TD120x devices. One of the main use is to have multiple sensors communicating to a sigfox gateway. The communication get benefit of the nice ultra narrow band RF transceiver included in the chip.
TD LAN is based on GFSK modulation on 25kHz channels working at 9600bps.
I did really remember where but I read it could reach long distance in the best conditions, so as it could open many opportunities, I wanted to test it in real conditions to see what we could get from it.