The TI-57 has a multiplexed 12-digit common cathode LED display. The corresponding 8 segments of all 12 digits are connected together; sort of. It turns out that TI economized on IC package pins by ”doubling up” the decimal point segment...
Rcl57mcu wants a 3.5-5V supply. So, even if I could resurrect the dead BP-7 NiCd pack/lid, it won’t work for this upgrade. I will instead recycle the tried-and-true USB charged 3.7V LiPo supply that I’ve used for HP Classic, HP-28S, and TI-58/59 supply...
Fault label: "Numbers keep changing".2024-03-01Switched on, set dials to maximum. Leftt around 28.8V and drifiting, right around 32.88Dials set to minimum.Left side very slowly descends to 14.3 volts, terminals are at -0.424 volts.Right side slowly descends...
This is a switch-mode PSU, so the mains is rectified to around 400 volts DC inside. Extra care is required to avoid touching this dangerous part of the PCB. This can be remote controlled by GPIB, RS232, USB or Ethernet. The user manual is here: CPX400S+SA+SP_Instruction_Manual-Iss9.pdf...
The display driver includes a command to invert the display and I have included a facility to choose an inverted display in the Settings app. I am still undecided as to which setting is more readable, however after implementing the analog clock app shown...
Right after the assembly, a basic test confirms the modules work, though the pulse generator frequency is somewhat off. Replacing a 6.8 kΩ resistor with a 4.7 kΩ should fix this. When one module is fed with the 1 kHz signal (from the oscilloscope reference...
Everyone respected my hacker alias and called me 'crip' when I arrived...even got a nametag: "Crip Lishus" - hellyeah! (Given names are so boring and prescribed. It's nice to reinvent ourselves and our identity to match what we like and...
Now that we were getting out of the concept realm and into the real world tangible stuff, my anxieties began to relieve a bit. It was time to take some measurements ! I rolled over to the nearest bus stop, and took out my midnight measuring tape...
The big hacker day was upon us and the gears were in motion! Julia jumped into action during morning solo hacker time. She went to the Mission Fabric Outlet store to find our throne-worthy textiles, as well as coordinating with a participant...
Julia and I rushed over to TAP plastics, hoping to get our acrylic sheet before closing. On the car ride over, I opened my CD case and asked Julia, "is there any music thatyou'd like to hear?" "You just have old people music, right?'" she said. She wasn't...
Once we got back to my apartment, the fatigue began to set in. It had been a long day already, with nonstop running around. I asked Julia if she could wait for a few minutes while I rested. She was totally understanding and didn't give me...
The serial port pin-out is cunning designed so that you can connect to a PC with a simple modem cable, or daisy-chained with other TTi devices. 1 Power to optional PC-02 2 TXD Transmitted data from instrument to PC 3 RXD Received data to instrument from...
The first step, after wiping-off the accumulated grime and surface corrosion, was to assess what I have. Within the very large - and very heavy! - case were four cards - an MZB-3 CPU card, a VDU-2K (composite video only) 'graphics' card, an FDC-1 Floppy...
I got this idea based off of a research paper a friend showed me and decided to go full prototyping mode with it!So let's say we have two tapes right, E is our tape with magnets on it, which is slightly longer than D (which has hall sensors). They are...
Initially, I roughly design the device to meet the following points: Slim and smallCellular connectivityGNSS -based location trackingLow-costBattery-powered and Rechargeable Working on the schematics, I was able to achieves those points and choses...