He needs portability. The missing piece is a USB I/O board that plugs into your phone. Of course this means having a phone that can be the host device and not just the peripheral.
I designed and built several I/O devices like this for myself, well to sell to other people really.
The I/O mix for one of my boards is a follows:
4 "Universal" inputs (0-20VDC, Thermistor, 0-20mA, Binary state and 32 bit counter)
4 12VDC @200mA binary outputs
4 One-Wire sensor bus ports (Dallas/Maxim temperature sensors etc)
2 0-10VDC analog outputs
RS485 port for multidrop network comms, i.e. Modbus/Bacnet etc
CAN port for I/O expansion (multiple boards acting as one on a CAN network)
USB device port for either firmware update (mass storage) or USB CDC serial comm port for config, direct I/O control
Powered by 12VDC or 24VAC
NXP Cortex M3 32 bit processor @120MHZ
Primarily intended for building automation but still general purpose enough for many other things. I use then for
lawn watering, door bell control, lighting.
Has a basic expression parser for interpreted basic logic. Expressions can be stored in flash as can dynamically created user variables.
Expressions can also be nested and scheduled for some level of automated behaviour. Everything is accessible via the USB serial connection.
The problem is that even my cost for a board like this is many times the price of the cheapest Raspberry PI. But then having very little real world I/O
(and large volumes) is how you can achieve a price like that.
Anyway, if a phone can interact with a USB CDC device then it could control one of my boards. I am going to have to try that out myself now.
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He needs portability. The missing piece is a USB I/O board that plugs into your phone. Of course this means having a phone that can be the host device and not just the peripheral.
I designed and built several I/O devices like this for myself, well to sell to other people really. The I/O mix for one of my boards is a follows: 4 "Universal" inputs (0-20VDC, Thermistor, 0-20mA, Binary state and 32 bit counter) 4 12VDC @200mA binary outputs 4 One-Wire sensor bus ports (Dallas/Maxim temperature sensors etc) 2 0-10VDC analog outputs RS485 port for multidrop network comms, i.e. Modbus/Bacnet etc CAN port for I/O expansion (multiple boards acting as one on a CAN network) USB device port for either firmware update (mass storage) or USB CDC serial comm port for config, direct I/O control Powered by 12VDC or 24VAC NXP Cortex M3 32 bit processor @120MHZ Primarily intended for building automation but still general purpose enough for many other things. I use then for lawn watering, door bell control, lighting. Has a basic expression parser for interpreted basic logic. Expressions can be stored in flash as can dynamically created user variables. Expressions can also be nested and scheduled for some level of automated behaviour. Everything is accessible via the USB serial connection. The problem is that even my cost for a board like this is many times the price of the cheapest Raspberry PI. But then having very little real world I/O (and large volumes) is how you can achieve a price like that. Anyway, if a phone can interact with a USB CDC device then it could control one of my boards. I am going to have to try that out myself now.