Some notes how to build a sensor that can be driven by 3 AA rechargeable battries for up to 1 year.
The web is full of examples how to build a temperature sensor. I want a sensor that is connected to my Wifi, can be driven by batteries for months and has an adequate resolution and precision.
This leads me to the following parts:
You always thought that end-to-end encryption in your favorite messenger like WhatsApp is a big deal? Or is it even not supported? Well, here is an example showing how “new” this feature is and it works for 15 years now. Using a Unix system (macOS, Linux etc.) it is a one-liner to send encrypted messages using the commands nc and openssl.
In this article I want to present the WiFi board I have developed for my Z80. It should be no problem to adapt it to different processors as I utilize a 16550 to connect the serial interface of the USR-WIFI232-T to the Z80 bus as you can see in the circuit.
Meanwhile I have soldered most of the Z80 parts on some board connected by a bus board. I will describe the complete system running CP/M 2.2 in the upcoming posts, board by board. Continue reading Z80 work in progress
I have found an old Z80 computer which was used in production in the 80’s. Specs seems to be a video card (or let’s say, a text card with video output), a Z80 MCU, 5,25″ floppy disk drive and a keyboard interface.
We all know that the raspi is a small and neat device for controlling our LEDs but sometimes I miss the possibility to add hardware to a “real” bus like a real CPU has. Sure it is possible to imitate a bus what is called bit banging. This way you can control external hardware like LCDs or writing data to external SRAM faster than utilizing SPI. So we were interested how fast the Pi can really switch these pins.
This is another project building a single board computer with an Z80 MCU alongside some RAM and ROM. In contrast to other well known projects I want to utilise an EEPROM which is very easy to handle. I also want to build a computer that works autonomously including an user interface and does not need additional microcontroller or a PC since both would be more powerful than the actual processor.
It is inspired by the SBC project by Grant Searle and therefore runs his modified version of Microsoft BASIC for the NASCOM computer. I further modified it for this SBC.
Before I explain the details, here is the result.
The specs are:
