Recent content by martinn

I have been playing with the axe401 28x2 shield, I am trying to create a low power use datalogger and the 28x2 hardware interrupt is brilliant. I have been try to have the 28x2 sleep until an interrupt or the minutes (for each hour) reaches 59 minutes, the interrupt works fine, but sleep is not...

I love the AXE401 shield, the same size as the AXE110 datalogger and so much more flexible and powerful; 3V and sleep using hardware interrupts will extend battery life, it just needs a RTC (that likes 3V). I hope that I am missing something bloody obvious, but I cannot get the I2C to work on...

Is there a 'drop in' replacement for the DS1307 chip, which is more accurate, I mean, keeps better time over a range of weather conditions (temperature). I have a fountain controller that activates at 00 and 30mins (during daylight) and the DS1307 drifts a few minutes over a couple of months...

I am using an Axe110 datalogger with a 18M2. I have a simple normally open reed switch connected between power and input 2, the reed switch is connected via 300mm of insulated wire (not shielded cable). The Picaxe registers a changed input when I touch the reed switch wires, initially it was...

When I use Setfreq M2 with an 18M2 the sertxd works at 2400 and pauses are twice as long, however, when I use Setfreq M1, the sertxd works at 600 (not 1200) and instead of a 15sec pause taking 60 seconds it is taking 120 secs. Is this correct? Martin

Has the problem with the 18m2 writing to larger external memory (24LC256/512) been resolved with a firmware update yet? Martin

Which is better coding and or lower load on the picaxe to create a timing loop. A for/next or do/loop (both a similar bytes). Another appraoch could be a long pause with polled interrupt, but I was more interested in the for/next do/loop question 'for/next for w0 = 1 to 6000 'combined with...

Hi I am using pulsin on an 18x to read an x-band motion sensor (www.parallax.com), it works fine at normal clock speeds, but when I underclock the chip, the program does not run properly, that is, it constantly resets the chip. The underclocking works fine if I comment out the pulsin line, and...

I have built several passive infra-red (PIR) based Picaxe data-loggers that record the number of people walking into the detecting area, these work well, however, PIR is limited to about 8-10 metres. I would like to build a counter that covers a width of 30-50 metres without having to have a...

I am playing around with 315mHz wireless units, I am having problems with Picaxe receiving a signal via serin when not attached to the receiver, which I assume is interference. I have used both an 18x in the datalogger unit AXE110 and an 8m on a Picaxe 80 Proto board. Currently I have a 10cm...

I have a datalogger running off a 12v lead acid battery. Is there any way for the Picaxe that is monitoring battery voltage to shut the datalogger down when the voltage gets to a predetermined level (that is, before damage occurs to the battery)? The only low power idea I have had is to use a...

If I wanted to measure how much force was being used by a drill going into a piece of wood, assuming a known force on the drill (e.g., a 1 kg weight) and a known drill bit diameter, fluting, a fully charged battery, etc, would it be possible/feasible to measure the current load on the motor...

I am summarising data collected over an hour, each hour the data is written to an eeprom. To record the hour the data was collected for, I simply use the current RTC reading (converted to decimal) -1. This works fine for all hours except midnight (hour 24) where it returns 255 instead of 23. I...

User interaction for set program parameters I have searched the forum, and may be I have missed it, but what I am trying to do is have the user be able to set some parameters for the program. Currently I use the memory_full routine (as used by the wizard) to have serin wait for “G&#8221...

Ignoring all other factors that can be done to maximise battery life (e.g., underclocking). Will using 4 x AA batteries via a diode to reduce the voltage outlast 3 x AA batteries (of the same batch)? Martin