The SRF01 is a popular ultrasonic sensor used primarily for range finding applications. [Jaanus] discovered that they had a few flaws, including not working after being dropped. The faulty ones began to pile up, so he decided to tear one apart and put his engineering skills to use.
The SRF01 is unique in that it only uses a single transducer, unlike the SRF04, which uses two. Using only one transducer presents a problem when measuring very close distances. The transducer emits a pulse of sound and then must listen for the echo. The smaller the distance, the smaller the time interval between the pulse and when the echo returns. There is a fundamental limit to this time as the transducer has to recover from what is known as ringing. [Jaanus] discovered that the SRF01 solves the ringing problem with the use of a PIC24’s ADC and its 500 ksps (kilosamples per second) rate. This allows it to measure very close distances.
Be sure to check out the teardown for more details on how the SRF01 works.
Ready to feel inadequate with your programming skills? You’ve been warned. Take a look at [Voja’s] single chip video game console using the PIC24. It produces the VGA signal, 5-channel sound, and is presented in a gamepad form-factor with directional pad and two buttons.
He’s been working with PIC24 for a while now generating VGA signals, and he decided it might be fun to create a 2D video game… so he decided to see if he could program a replica of the old Spectrum game Jumping Jack (play it online here).
It uses a PIC24EP512GP202 microcontroller, complete with 512K flash memory, 48k data, and a whopping 28-pins. The game, which is extremely well documented, is laid out over on his projects page. It makes our heads spin just looking at it! This is a great project to compare with the ArduinoCade from last week. Both do an amazing job of pumping out audio and video while leaving enough room for the game to actually run.
Anyway, enough talking about it — just take a look at the following demo!
Continue reading “A Single-Chip Video Game Console”