Original article: PT2314 WiFi Audio Processor with ESP8266 Web Interface PT2314 + ESP8266 audio processor board I have been covering the PT series of audio DSP ICs PT2258, PT2315, and now PT2314. This one has 4 stereo input channels and a full tone control suite over I2C. Instead of front-panel knobs, I moved all controls to a web interface running on an onboard ESP8266. Volume, bass, treble, input selection, and gain are all adjustable from a phone browser. Settings are saved in EEPROM and survive power cycles. PT2314 Overview The PT2314 is a 4-channel audio processor from Princeton Technology (pin-compatible with TDA7314), controlled via I2C at address 0x44, supply 7.5–9V. Key specs: • 4 stereo input channels • Input gain: 0 / +3.75 / +7.5 / +11.25 dB • Volume: 0 to -78.75 dB (1.25 dB fine + 10 dB coarse steps) • Bass / Treble: ±14 dB in 2 dB steps • Speaker attenuation: 0 to -38.75 dB per channel External components set the tone frequencies: 2.2nF ceramics for the treble shelving network and 5.6kΩ / 100nF pairs for the bass feedback loop. Circuit and PCB The board runs on 9V DC; an AMS1117-3.3 LDO steps it down to 3.3V for the ESP8266. AGND (pin 2) and DGND (pin 25) of the PT2314 share a single connection point and are separated in layout to prevent digital switching noise from coupling into the audio path. Ground fills on both layers, stitched with vias, reinforce this. I2C lines (SCL/SDA) are routed well away from all audio signals. PCB fabricated from JLCPCB. Schematic — PT2314, ESP8266, LDO, and tone filter network Two-layer PCB with ground fills on both sides Firmware and Web UI Firmware uses four libraries: Wire, EEPROM, ESP8266WebServer, and WiFiManager. On first boot the ESP creates a hotspot (PT2314_AudioAP / 12345678). Connect to it from your phone, pick your home WiFi in the captive portal, and from then on any browser on the network opens the control page. The dark-theme UI has sliders for volume, bass, and treble plus input and gain selectors. Five built-in presets: • Vocal: Bass 0, Treble +3 • Bass Boost: Bass +5, Treble -1 • Pop: Bass +1, Treble +2 • Rock: Bass +3, Treble +3 Slider moves hit the PT2314 over I2C in real time, so no page reload needed. Dark-theme web UI on mobile browser Testing I tested with a Class-D amp and a Bluetooth module on Stereo Input 1. The Bluetooth output needed +7.5 dB input gain to level-match a direct AUX source. Audio was clean with no audible noise floor at normal listening levels. At high volume with bass boost maxed, the amp handled it without clipping. Pop noise note: switching inputs or powering up produces a click. Make sure the downstream amp has a mute-on-startup feature, or add a relay delay on the speaker outputs. Battery supply gives the cleanest results; if using SMPS, add extra filtering on the 9V rail.

I have been working with energy metering ICs for a while now. After trying BL0937 which has a pretty straightforward control interface, today I finally got my hands on the BL0940. Both are similar, because they are single-phase energy metering IC but what surprise me the most is its feature set. Unlike the simpler BL0937 ICs in the BL series, the BL0940 gives you voltage, current, active power, energy accumulation, phase angle, power factor and temperature without the need of component calibration, and all data is accessible though UART or SPI. But for now this tutorial is focused on SPI communication mode. You just pull the SEL pin HIGH for SPI, and the IC switches its entire communication interface. I built a complete Arduino library around this IC with five ready-to-use examples. The total component cost is very low a 1 milliohm shunt resistor, a voltage divider network, and a few capacitors is all you need on the analog front end. This is a open source project you can access the design files through GITHUB, I have made a dedicated PCB from JLCPCB and tested it out with real time energy monitoring in my lab. See the full article from my Hackster profile.

I do love making circuits that can power my car amplifier from my car battery. Not just because it is 12V but my amplifier system needs a dual rail power. This is the major problem in transistor based amplifiers because they need a higher voltage with a stable ground reference thus a dual rail power supply concept comes and it hurts me more when I just have a simple 12V battery. Something like +24V and -24V. You need a way to step that up and split it into two symmetric rails. The obvious thing that came to mind is using a transformer that can do it. That's exactly what this module does. It's a pre-built push-pull DC-DC converter board that takes 12V DC in and outputs 24-0-24V (that's +24V and -24V with a centre-tap ground) at over 5A. I picked one up for an amplifier project, and I thought it was worth breaking down how it actually works. The controller IC running the show is the KA3525A, a classic SMPS controller that has been around for decades. I will show here how the push-pull topology works, and how to wire it up safely. For real-world power-on and load testing. How to Use It: Connect your 12V DC source to the input terminals. This module does not have a reverse voltage protection feature. Use a source capable of supplying enough current. At 5A output on the 24V rails, the input side draws significantly more 10-12A from the 12V supply due to the step-up ratio plus conversion losses. Use thick wires (at least 14-16 AWG) and a source rated accordingly. A 12V lead battery or a beefy 12V switching adapter works well. Avoid unregulated wall warts. Connect +24V and -24V to your amplifier's V+ and V- supply pins. The 0V centre-tap connects to your amplifier's ground. Some push-pull converters can develop voltage at no-load because the feedback loop. Start with a light load and verify the output voltages with a multimeter before connecting your amplifier. My Experience: I got this module to pair with an audio amplifier that needed dual +/-24V rails but I only had a 12V bench supply handy. It delivered on its core promise stable +/-24V rails from 12V input, powering the amplifier, I have checked it using a multimeter. As the output capacitor charges it shows a significantly higher around 25V. But I have also tested it under some load for which the results are given here. Build quality is what you'd expect from a generic module. The PCB is decent, solder joints are acceptable, and the IRFZ44N MOSFETs are genuine. The transformer is the biggest component on the board and it's wired reasonably well. What you need to find is just a good component vendor in case you are building something like this on your own. #powerconvertor# #voltageConvertor# #PCB#