Modulo Breakaway?


#1

From the schematic, as a halfway-point between using the Modulo as a development board and actually starting to integrate the ASR-1 into my own circuits, it looks like I should be able to break away the ASR-1 from the Modulo and use it on it’s 8 header pins to start to connect it up.

Well, it looks like I /almost/ should be able to do this. The 8 pins bring out the 4 I/O pins, power, and TX/RX , and one of the 4 top pads is a reset pin (to reset the ASR-1 from the host), but I don’t see in the schematic (https://developer.afero.io/docs/en/images/ModuloSchematic.pdf) where the HOST_INT_B interrupt pin is exposed. I’d need that pin to signal the ASR-1 has data for my controller, right?

There are 2 pads on the bottom of the ASR-1 breakaway labeled CTS and RTS, but I don’t think thats actually what those pads are. My guess is that those are likely RES1 and RES2 pads for programming. I’m still kind of learning the platform, but I think I’m going to need HOST_INT_B if I want to interrupt my MCU in order to pull data off of the ASR-1. I need to see if I can design a small board like that breakaway but maybe with 10 pins instead of 8 and bring out pins for both reset and HOST_INT_B. Let’s see if my Eagle skills are up for it. :slight_smile:

Cheers,

Joe


#2

You’ll actually need more than HOST_INT_B to communicate from a controller. You’ll need to use the Afero SPI afPro SPI protocol which is documented here: MCU to ASR-1 Communication.

That protocol requires the use of 5 pins: MOSI, MISO, SCS, CLK, and INT (as labeled on the Modulo board). The ASR-1 uses the interrupt line to let the controller know it is ready to receive data.

The TX/RX pins on the ASR-1 are currently only used for displaying version information. The RTS/CTS pins are not currently used as the ASR-1 does not implement any flow control.

Hope that helps,

…Zz


#3

Man, I know that. Where was my head? I guess the use case I was thinking of was basically the opposite - not connecting the tiny board to an MCU, but the opposite - using the breakaway board without an MCU and just controlling the I/O pins via profile. I’d made some notes to myself that the breakaway on the modulo board looked like it’d work standalone, then completely brain-well, you’re know. :smile:

Cheers,

Joe


#4

So just to be clear, using the breakaway board with an MCU is totally doable. You can use the 4 IO pins as outputs to control other circuits or inputs to read sensors and such. The breakaway board only needs power. The IO pins only need a profile. So for example, a motion sensor can be easily built by connecting the motion sense line to one of the IO pins, configure the IO pin as an input, and then publish the profile. No other pins are required except providing power to the breakaway board. I’m guessing that’s what you wanted but got thrown off by the interrupt pin which is only required for the MCU case.