With the 16×16 123RGB panel base on WS2812b, I have 256leds able to consume up to 50mA each. I want to use this with a limited current under 3A and want to ensure using software, this limit will not be reached. This article detailed my code for doing this.
Each led value is stored in a int array where each value is containing rvb values.
As described in a previous article, I’m investigating ws2812b leds provided with RGB123 board. These leds are providing a lot of light, which is a good thing but also require large power supply to light them on. As in my system, I want to control power to not overload the battery, I’m tring to predict current need and limit it.
In fact, the final equation is really easy to get. According to my different measures, the current is really linear for each of the color, equal for each of them too.
As a consequence, the final current estimate is :
I(mA) = 1 + R/16 + G/16 + B/16
A lot of you are coming to my blog for RF433 with Raspberry PI content (here). This article is a small part of a larger project I have. As part of this project I built a Raspberry Pi shield including an RF433 emitter and receiver. I could sell this shield to some of view if it make interest to you. To make it I selected emitters and receivers to get the best quality / price compromise. (read my other articles on this topic) I could sell it around 60€ + port.
Update : chek this article for all informations on the shield and buy it !
RF433 shield for Raspberry PI v0.1
My question to you is : would you be interested in a such thing ?
If yes : leave me a comment with your email address ( I’ll will remove this address before validating it )
RF433 Raspberry PI shield v1.0
Here is the Version 1.0 with antenna connector integrated to PCB.
The last step to use a ATMega328P / Yabbas from the Arduino IDE is to plug it with a FTDI cable (TTL RS232 over USB). Personnally, I’m using the TTL-232R-3V3 to do it. The first step was to create an adaptor to transform this cable output to the YABBAS pinout.
Recently I made a Yabbas arduino system ; this is a low cost arduino (7€) you can DIY. I’ve made it with a group of people from my city (look here) and my daughter. During this session we have finished the prototype but not had the time to flash the AtMega328P.
Now this is done using my Arduino Leonardo as an ISP programmer. I’ll detail the way I’ve done it here
After mixing different source of information, I was able to decode some Oregon Scientific sensors to get Temperature and Humidity indication, over the air, on 433.92MHz, with a Raspberry PI system. This article gives some details of this adventure …
You follow this implementation at your own risk…
If you are interrested in this article, you could also take a look here where you can find a RF433 shield and the associated code
After having test some receiver, naturally, I’ve tested some transmitters, the objective is the same : get the best coverage in the same condition : I would say poor conditions. Lots of wires going every where and an antenna make with a simple 17.3cm wire. As expected, results vary regarding the emitter used. Reed more to get details.