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  1. neiltechspec

    Maths Help Needed

    Hiya all, I have a Wideband Lambda Air Fuel Ratio display, the controller also has a linear voltage output which can be used for logging purposes. Which is what I want to do. The logging bit I can handle ok using an "openlog" which I have used before for logging hourly solar inverter stats and...
  2. neiltechspec

    Maths Problem

    Following up on my model railway scale speed display, I seem to be having trouble trying to get my head around the maths required. The start & stop timing sensors are 100mm apart, N guage scale is 1:148. So I calculated this to be 1 Sec = 33MPH. The problem I'm having is how calaculate the...
  3. neiltechspec

    Quick question on pullups

    Anybody know the comparative pullup value between pins on 08M2 pins C.1 & C.2, are they the same or wildly different ?. Or would I be better off using separate resistors, 47k for optical rx collector pullup to 5v. Neil.
  4. neiltechspec

    Ideas for measuring model railway loco speed

    Using an M2, I want to measure loco speeds. I have two IR sensors (TX/RX) in small packages mounted in the track 12 inches apart. So, 1 Foot Per Sec = 0.6818 MPH, for N Scale multiply by 148 gives me scale speed. Should be easy enough. Thinking of using the 'pulsin' command to measure time...
  5. neiltechspec

    Turning Servos OFF until inputs change

    My points controller does 5 servos activating sets of points on my N Guage Railway. Inputs are switches and can be left in either position (on / off), when a switch changes I want to move the appropriate servo & then turn the servo off after about 200ms (should give enough time for servo to...
  6. neiltechspec

    Problem trying to order from PICAXE store

    It seems I am unable to place an order & pay by paypal. Keeps coming up with 'Failed address validation %1' The address it shows is correct & is as extracted from paypal. I have never had this problem before. Any ideas ????.
  7. neiltechspec

    LCD Contrast Pin Current

    Voltage seems to be between 0v & 1v approx, depending on display. As per the title, does anybody have an idea of how much current the LCD contrast pin draws. I'm looking to drive it off the DAC pin, should be possible if very low current required I would have thought. Neil.
  8. neiltechspec

    Unusual LCD Display

    Has anybody successfully used one of these before, or has any idea what driver chip it uses ?. It's a 8 X 2 LCD display that seems to be numeric only (and a decimal point) Using RevEd AXE133 code, 254,1 clears the display ok 254,192 positions cursor to beginning of 2nd line But 254,128 is not...
  9. neiltechspec

    Neoway M590 GSM Texter

    Found a Neoway M590 GSM SMS Text Module on fleabay for £7.90. Came setup for 9600baud, uses TTL simple AT commands for comms & runs off 3.3v It's really easy to use, but suggest the datasheets are studied as well. #rem M590 GSM Texter 9600baud V1.0 Sept 2016 On Power Up module sends :-...
  10. neiltechspec

    HSEROUT on an 08M2

    A quickie question on hserout. Noting this statement in Manual 2 - The hserout command is used to transmit serial data from the fixed hardware serial output pin of the microcontroller. It cannot be used with the serial download output pin - use the sertxd command in this case. With -...
  11. neiltechspec

    ADC10 Calculation

    Having a bit of trouble getting my head around the calculation need for a Oil Pressure Gauge. The sensor gives a linear o/p from 0 to 100 PSI. 0 psi = 0.5v 50 psi = 2.5v 100 psi = 4.5v Normally I would use - Supply Voltage 5v adcconfig 0 readadc10 w0 Then it would be easy to convert the...
  12. neiltechspec

    calibadc seems to screw up port C.7 on 20M2

    Title says it all really. I'm using a 20M2 driving two 7 seg Common anode displays directly through 470 ohm resistors to limit current to approx 5 mA per port. Units digit on port B & Tens digit on port C, so port C.7 has segment 'G' on my tens digit. Driving the ports low turns on the...
  13. neiltechspec

    TLC59116 Confusion

    Trying to get a TLC59116 - i2c LED PWM driver to work. I can't seem to understand the datasheet around device addressing. Trying the code below, but doesn't work :- hi2csetup i2cmaster,$c0,i2cslow,i2cbyte 'set base address hi2cout $d0,($00,$01) 'enable LED all call address & turn on OSC...
  14. neiltechspec

    Having Trouble with Fahrenheit Conversion

    Using a HT21D i2c Humidity & Temp sensor, no probs with Humidity & Temp in degrees C. But I can't seen to get my head around converting negative degrees C to degrees F. Any help appreciated, relevant part of code is below (with below 0 remmed out). Neil. symbol temp12 = w7 symbol adjtemp =...
  15. neiltechspec

    HTU21D Maths question

    I'm playing around with one of those HTU21DF sensors. Reading data ok & masking off the two status bits ok, but I'm having trouble trying to work out the maths for actual RH & actual Temp conversions for an M2 chip. Basically they are :- actualRH = -6 + (125.0 * rawRHData / 65536) &...
  16. neiltechspec

    RTC Clock Setter using GPS

    Many of my projects use RTC Clock Modules, either DS1307's or DS3231's. I got fed up with try to set the time from the PC and could only get within 3 or 4 secs, so came up with this today. Uses a ublox NEO-6 GPS Module PICAXE 28X2. Needs an X1 or X2 chip for the bit shifting capabilities...
  17. neiltechspec

    What's an M2 chips ADC input impedance ?

    As subject - What's an M2 chips ADC input impedance ? Does anybody have a quick answer. Neil
  18. neiltechspec

    ublox GPS

    Has anybody managed to alter the NMEA message config on one of these GPS modules. I only need GPRMC, but with no skipped fields - by default speed & course are skipped if not moving. I need the skipped fields to read 000.0 & 000.0 Neil
  19. neiltechspec

    AXE201 Datasheet ?

    Thinking of buying one of these, but there seems to be a problem with the datasheet. The link shows Manual 1 and not the details of AXE201. Does anybody have the correct datasheet (cct diagram) ?. Neil.
  20. neiltechspec

    The need for decoupling

    So, yet another problem has been resolved today by the addition of a decoupling capacitor. (Not me !). It's been seen so many times now. So why don't Rev Ed put the need for Decoupling Capacitors in big Red Letters at the start of all the manuals ??????. Seems an obvious omission to me. I...