From Earlham Cluster Department
Possible Commercial Product
- There may be general commercial products to solve this problem.
- See references
- Determine required sensitivity and periodicity for each sensor.
- Mike said that sensitivity should be secondary to ruggedness and cost because the sensitivity that we are looking for is not high and most sensors will meet our needs. Thus, our approach should be to find sensors that we think will work and then send him the specs for him to OK.
- A selection of sensors from Hydrolab.
All-in-one Units, "Sondes"
- Most use batteries as the primary power source.
- Most have other features and sensors not listed in the matrix.
RTP - Ruggedized Wide Range Temperature Probe
- 9 or 12 bit resolution
- 12 foot CAT 5 cable
- Dallas Semiconductor DS18S20 or DS18B20 sensors
- uses 1-Wire communication protocol
The RTP temperature probe is designed for wide temperature range applications requiring excellent chemical resistant properties and sensor submersion.
Nitrate Levels (NO3?)
- Mike says that we could build a turbidity sensor using LEDs and fiber-optic cables without too much difficulty. He is willing to help with construction if necessary. However, we both agreed that finding an assembly that meets our need would probably be the first course of action.
- Power over ethernet? not supported by TS or Gumstix.
- Heating and cooling.
Embedded Arm Product Matrix
| SBC || Type || DIO lines || A/D Converter || Price
|| ARM || 20 || 8 ch. 12-bit (opt) || $149.00
|| ARM ||20 || 5 ch. 12-bit || $149.00
|| ARM || 30 & XDIO* || 2 ch. 12-bit || $179.00
|| ARM || 55 (35 XDIO) || n/a || $219.00
|| ARM || 20 || 4 ch. 8 bit || $129.00
|| x86 || 38 (IRQ) || 8 ch. 8 bit || $319.00
- eXtended Digital I/O functionality including pulse-width modulation, quadrature and edge counting, and pulse timing with IRQ/DRQ support.
- TS-DIO64 Digital I/O Board, which is a 8-bit PC/104 (standard format) peripheral board that provides 64 digital I/O points (32 inputs plus 32 outputs). Up to 4 TS-DIO64 boards may be installed into a single system, enabling up to 256 DIO points (128 inputs plus 128 outputs). The TS-DIO64 DIO functions are compatible with any PC/104 SBC including all the Technologic Systems ARM and X86 products.