I have just encountered the need to read a digital dial indicator for another personal project. However, most of these digital dial indicators are “expensive” (normally cost about 30 – 100 USD), so I figure to just get a cheap digital caliper costing about 3 USD to start with. I totally understand that a cheap digital caliper might have different data protocols, but from what I gathered on the internet, most of these Chinese digital measurement tools use similar format — a clock and a data.
Arduino output matches (closely) caliper reading. There are some discrepancy, but I think it the poor caliper that is displaying wrong data
Not able to find my USB logic analyzer and my oscilloscope is dead, I decided to use an Arduino as signal analyzer. read more
Yes, you heard it right, you can use an audio speaker as stacking stage for high magnification work. It was during the Chinese new year when almost all businesses are shut down for almost two weeks in China, my speaker for PC was behaving strangely, after all, I have been using the pair for about 7 years. So, I started investigating what was wrong. By touching some wire, the speaker made some noise, and since I was testing some setups for high magnification stacking, the movement of speaker cone caused by noise immediately drew my attention: can that movement be used for stacking? I was pretty sure it can and I posted the idea on a forum which drew some attention.
After some more experiment on my own with above circuit, I think it is a very viable solution.
When taking pictures using a macro lens, shallow depth of field usually mandates a rather small aperture to gain sharpness. With automatic lenses, stopping down is not a problem because the camera keeps the aperture wide open during view finding, unless you press the depth of field preview button. Only when camera is taking a picture, does it set the true aperture to whatever you set it to for exposure. However, if you ever used a manual macro lens, stopping down the lens cuts the light significantly, making it really hard to see through the view finder and focus. This is particularly hard for higher magnification macro lenses such as Canon MP-E 65mm f/2.8, Laowa 60mm f/2.8 2x and lenses on extension, etc, where it is almost impossible to focus even at f/11.
Good news is that there is a simple and easy to do DIY solution to this problem as shown above and the difference can be day and night. more …