My sensorboard MYS 1.0beta

[Anticimex]

The ATmega has internal pull-ups on most IO. Is it not adequate to use those for pulls for I2C and sensors? Are they to weak?

[Mrlynx]

The internal pullups is about 50K but for 1-wire and humidity you need a 4,7K ohm resistor.

[djdworks]

@Mrlynx i'll be very happy to buy 10 of them

[p0lar]

Im in for a few. what do I need to provide you with?

[jendrush]

This is sensor board i've made 2 days ago :)

[Mrlynx]

I have updated the layout and added caps to the voltage dividers.
I am now going to order components for a batch of 100 boards.
what pull-up resistors and voltagedividers do you need?
I think that I will supply the kit with some 1K, 4,7k and 10K.
The price for a kit will probably be 7$ + shipping. Just add an Arduino pro mini, radio and sensor to make it a node.
@djdworks and @p0lar are first in line when they are ready.
@jendrush nice work.

[tjay4x4]

@Mrlynx I'm in your boat, wanna get 10 boards.

[jendrush]

@Mrlynx said:

nice work.

Thank you. This is only temperature board, but best part of this board is cost.

Piece of PCB ~30 cents,
pins ~30 cents,
power connector ~10 cents,
capacitor+resistor ~ 10 cents,
3.3V regulator ~ 10 cents
:) less than 1$ for complete board, and about 7$ for all parts including radio, arduino mini, wall usb charger, and cables:) This is power of MySensors!

Thank you @Hek, and rest of the team!

[Mrlynx]

Schematic for the updated MYS 1.1 mys11.pdf

[djdworks]

I had a look to PDF schematics and i have a request to include SDA and SCL pins since many sensors uses such pins if possibile. Thanks a lot.

[Mrlynx]

Only problem is SDA and SCL are located on separate pins on top of the pro mini module and not in the normal row of pins. (A4-A5)

[Zeph]

SDA and SCL seem to come in two places on APM's - inside the row of pins, and sometimes at the end opposite the serial programming pins. A host PCB could allow either.

[Mrlynx]

I have now added SDA/SCL(A4/A5) to MYS 1.1
Is there any more ideas to be added before I send it for production?

mys111.pdf

[p0lar]

cool on the full kit price but can we also get just plain boards? I have a few home-built sensors that I need to upgrade :)

[djdworks]

Well done I'm very happy for SDA and SCL added on the board thanks a lot.

Yesterday night I had a deeper look into the PCB and i was thinking that if you add 3 pins with MISO, MOSI and SCK your board will be good also to build ethernet gateway or connect additional SPI device.

[Mrlynx]

I have thought about the spi channel but I cant really understand why the ethernet gateway sketch uses different CE/CS pins for the radio.
Why cant the radio use pin 9/10 and the ethernet shield 5/6?
Maybe @hek can shed som light on the matter?

[hek]

@Mrlynx

It was based on an example I received from @a-lurker back in January.

If it is possible for someone to rework the example using the normal configuration for the radio and ethernet (WizNet and ENJ) on the 5/6 please post an updated EthernetGateway (1.4) and pin configuration in a new forum thread.

[djdworks]

the CE and CS pin shall be different for each SPI you have connected on SPI bus.

The pins will act as follows

CE (chip enable) = with this pin, LOW or HIGH depending on the manufacturer, the SPI bus is connected like a switch to the device, when the device is not "connected to the bus" the pins will be in "high impedance" state. Sometimes CE is already connected with CS and is not available on device pinout.

CS (chip select) = this pin will enable the communication with the device.

I hope to have clarified the matter.

Some devices (like arduino TFT) have the possibility to have a dedicated SPI bus (MOSI MISO SCK CS RST) on any pin.

[Mrlynx]

I have now added a SPI-header (SCK/MOSI/MISO) and a smd footprint for a 24LCXXX flash memory.

[marceltrapman]

@Mrlynx said:

a smd footprint for a 24LCXXX flash memory.

Can you tell me how you wired things up?
I am looking how to do this but I am not sure.
Did you test it already?