Recent content by John Chris

I'm looking for a PICAXE 28X-5V based on the PIC18F2520. Can anyone suggest where I might find one of these? Without success, I have tried: http://www.phanderson.com/picaxe/ https://www.sparkfun.com/categories/124 https://solarbotics.com/product/28484/ I note that I have a number of...

Hi there, I have a brief question. I'm trying to determine the source of NUL characters transmitted spuriously in between RS-232 level transmissions from a 28X2 (...25k22 operating at 3.3 V) whose hardware serial lines are taken through an analog switch and the MAX3244 transceiver. Note that...

Hi there, My apologies if this issue has been discussed before, I performed a brief review of relevant posts and didn't find the answer, however, I didn't have too much time; my search was by no means exhaustive. I have the hardware serial lines of a 28X2 (3.3V, low-power version) connected to...

Hi there, I'm trying to diagnose the source of a behavior that I find to be strange on ADC0, ADC1, ADC2 and ADC3 of a 28X2 that resides on a custom PCB. Here is the code that I use: dbgporta: adcsetup = 4 readadc10 0,cntc sertxd(#cntc,",") cntc = 0 readadc10 1,cntc sertxd(#cntc,",") cntc =...

Hi there, I have a question regarding communication/handshaking with i2c. Generally the use of the PICAXE implementation of i2c means that one only has to think about an address on the slave device, and a variable(s) that either contains or will contain a value(s) being transmitted from master...

Hi there, I believe that the following archived post is relevant: http://www.picaxeforum.co.uk/showthread.php?t=972 I'd like to: 1) Convert a PICAXE Basic file to .HEX 2) Learn about the procedure for flashing a .HEX file onto PICAXE programmed PIC. If possible, might someone point me in...

I'd like to interface the 28X2 to a frequency output sensor. Connected to an I/O pin, using `count' function. Some properties of the waveform are: Voltage level: bi-polar, -0.5 to +0.5 V square wave, capacitively coupled frequency range: 2-6 kHz Is the count function suitable ... ? Is the...

I have a misbehaving 28X2 that may have experienced excessive writing to certain bytes in eprom ... Do we expect that the EPROM can be compromised a bit or byte at a time, blocks at a time ? Can one byte be compromised, while an adjacent byte remain functional ? Will the READ command return...

Hi there, I am wondering if anyone has any idea if there is a specified maximum number of EPROM read/write cycles? I have developed a 'WaitForTime' subroutine that writes the time obtained from an RTC to eprom roughly 4 times a second. It checks the current time against a set time that is...

Hi there, By placing an HSERIN command within a loop, one can effectively get away from the limitation imposed on the 'timeout' value (limited to approximately ~32s (65k ms) at 8 MHz). My question is, as I have implemented the looping in the code shown below, what is the estimated magnitude of...

Hi there, I'm working with the 28X2, and a BLDC motor with a low-level directional control lead. The stated input resistance for the motor direction lead is 10 kOhms, should I have any difficulty bringing this high with a Port B I/O pin. I send the pin high, and it remains so for less than a...

Hi there, I'm working with the uALFAT. I have looked through BCJKiwi's work on the uALFAT and am presently making sure I understand the subroutines used to deal with the HEX, DWORD ascii string output by the uALFAT that describes media capacity, and media free space. I would like to...

Hi, Is there a way to use bitwise logical functions such as OR, AND, etc or other PICAXE supported functions to implement a roll-over for a given set of numbers without using an IF statement. For instance the set of integers 1-12 describes the months in a year. Can we devise a simple...

Hi there, I am working with a 28X2 that has a DS1388 RTC on I2C. My goal recently has been to create a variety of subroutines that allow accurate scheduling of events according to local calendar time, e.g. a function that takes two calendar times and returns the difference in Y,M,D,h,min,s...

Hi there, I'm using the 28X1 to communicate with the Vinculum VDIP1 using the hardware serial pins. A command such as this, 'HSEROUT 0,("WRF ",$00,$00,$00,$08,CR,"AAAAAAA",CR) that I found in an archived post does what one would want - that is, write chars to an open file. In this case it...