Replacement of skylight in the little shed

The ‘little shed’ is about 30 years old and the fibreglass sheets in the roof providing a skylight have reached end of life, so they were replaced before hail destroyed them. A fairly local company rolls the exact same profile and colour of Colorbond steel sheet, so two sheets were ordered in the required colour and length and collected a couple of days later at Minto.

The sheets were replaced, but a solution was needed for the missing skylights. A solar / LED solution was chosen.

Above, a nominal 30W PVA, not optimally tilted, delivers about 15W max. Cost $50. Continue reading Replacement of skylight in the little shed

Initial review of ECO-LFP210 LiFePo4 (LiFe) battery

A ECO-LFP210 10Ah 4S LiFePo4 battery was purchased on eBay for a solar powered project, cost about $65 delivered.

Above, the battery (the Anderson Power Pole connector is an addition). The battery incorporates a battery management system (BMS), so protected against over voltage, undervoltage, over current, and cell balance is preserved. Continue reading Initial review of ECO-LFP210 LiFePo4 (LiFe) battery

Review of Shahe torque screwdrivers ZSQ-0.6 and ZSQ-3.0

This article gives initial impressions of two budget torque screwdrivers:

  • Shahe ZSQ-0.6: 0.1-0.6Nm; and
  • Shahe ZSQ-3.0: 0.5-3.0Nm.

They were purchased on Aliexpress from the “official Shahe store” for about $33 each incl shipping. There are no brand markings on the screwdrivers.

Above, the two torque screwdrivers, plastic bodies but mostly metal internal parts. Continue reading Review of Shahe torque screwdrivers ZSQ-0.6 and ZSQ-3.0

Origins of the PIK (PIC Iambic Keyer)

I rode my motorcycle over to visit Ray, VK2COX, and we rode our bikes across to Canowindra  (pronounced /kəˈnndrə/ kə-NOWN-drə) for a burger at the famous Garden of Roses Cafe.

Over lunch, Ray described his new cigarette packet sized CW rig build that he would take up onto the local hill on his block for a little play, and told me he was going to jam his favorite 3xNE555 CW keyer into it.

I offered to design him an accurate keyer based on an 8 legged DIP chip and less than a dozen parts overall. I designed the logic in my head on the way home to Canberra, and started programming it that night in May 2001.

Screenshot - 18_04_16 , 19_47_22

The PIK is described at PIK – PIC Iambic Keyer. Above is the generic circuit diagram of the PIK. Continue reading Origins of the PIK (PIC Iambic Keyer)

A low cost break-out board for STDC14

It is now near impossible to procure a genuine STLINKV2 or a good clone. Newer versions of STM32CubeProgrammer will not work with poor clones.

In pursuit of a small inexpensive replacement for the STLINKV2, the STLINKV3-MINIE is a candidate. That said, they can be difficult to source… mine is on 9 months wait from element14.

Above is the STLINKV3-MINIE (~$20). Continue reading A low cost break-out board for STDC14

Programming a PIC 12F510 using the DIY-150 programmer

A correspondent asked how to program a PIC 12F510 used in one of my projects using his DIY-150 programmer.

The DIY-150 programmer is quite an old design and there has been no development for more than 10 years, meaning no new chips added, though there are lots of online sellers of the now stale design.

The 12F510 is very similar to the 12F509 which microbrn v150807 does support. The 12F510 can be programmed by selecting chip type 12F509.

Alternatively, download the archive below and extract a modified chipdata.cid file which includes a 12F510, and extract it to replace the existing installed file.

The revised chipdata.cid can be downloaded here: chipdata.7z.

Review of inexpensive Chinese thermostat – DST1000

The DST1000 targets the market for inexpensive digital thermostats, the most popular being the STC1000. The novel features to the DST1000 is that it uses  a DS1820B digital temperature sensor (well probably a Chinese clone).

The problem with thermistor based thermostats is that they commonly have significant error, and although most firmware allows the user to enter a calibration adjustment, it is a fix at one temperature and does not solve the problem that the thermistor equation implemented in the firmware does not match the behavior of the thermistor. In my experience, calibrating at 20° might result in an error as much as 5° at 80°, unacceptable for lots of wide ranging applications.

It is sold with brief and inadequate / incorrect user instructions. Two were purchased to give a good chance one would work, and you guessed it, only one worked. The lower display segment of the first digit did not work on the fautly one, and the seller thought that was not a problem. The seller frustrated attempts to obtain a refund for the faulty unit.

Above, the seller’s pic of the DST1000. Continue reading Review of inexpensive Chinese thermostat – DST1000

Garden environmental telemetry project – part 5

Garden environmental telemetry project – part 1 laid out plans for a simple maker / DIY IoT garden environmental telemetry system.

This article documents a change to the sensor configuration and payload formatter adding another temperature and humidity sensor for the greenhouse.

The sensors are now:

  • ID=1 air temperature and humidity;
  • ID=2 soil temperature and humidity.
  • ID=3 greenhouse temperature and humidity.

The payload contains an 8bit payload version number then six 16bit values for the six sensors. This is parsed by the TTN uplink formatter.

RS485-LN firmware has been upgraded to v1.4. Continue reading Garden environmental telemetry project – part 5

Garden environmental telemetry project – part 4

Garden environmental telemetry project – part 1 laid out plans for a simple maker / DIY IoT garden environmental telemetry system.

This article documents a change to the sensor configuration and payload formatter in preparation for another RS485-LN.

The sensors are now:

  • ID=1 air temperature and humidity;
  • ID=2 soil temperature and humidity.

The payload  contains a 8bit payload version number then four 16bit values for the four sensors. This is parsed by the TNN uplink formatter.

function decodeUplink(input) {
  var payver=input.bytes[0];
  switch(payver){
    case 1:
      return {
        data: {
          field3: ((input.bytes[3]<< 8)|input.bytes[4])/10,
          field4: ((input.bytes[1]<< 8)|input.bytes[2])/10,
          field5: ((input.bytes[7]<< 8)|input.bytes[8])/10,
          field6: ((input.bytes[5]<< 8)|input.bytes[6])/10
        },
      warnings: [], // optional
      errors: [] // optional (if set, the decoding failed)
      };
    case 2:
      break;
    }
  }

Above, is the Custom Javascript formatter which writes the measured values into variables fields3-field6 of the data object.

To be continued…

Garden environmental telemetry project – part 3

Garden environmental telemetry project – part 1 laid out plans for a simple maker / DIY IoT garden environmental telemetry system.

Earlier experiments highlighted the disadvantage of analogue sensor connections. This article reports tests on sensors connected using digital signals.

Above is the Dragino RS485-LN LoRaWAN end node, about $90 incl shipping. In this application it will be used to read two MODBUS sensors (each with two data channels) and forward the data to The Things Network via LoRaWAN, then after some processing, RESTFUL submission to Thingspeak. Continue reading Garden environmental telemetry project – part 3