- #I2C VS UART PERFORMANCE HOW TO#
- #I2C VS UART PERFORMANCE SERIAL#
- #I2C VS UART PERFORMANCE SOFTWARE#
- #I2C VS UART PERFORMANCE CODE#
The sender passes a logic 1 by applying equal-and-opposite voltages on both lines at the same time. In this setup, the receiver reads the difference between the top and bottom channels. Mayhem aside, let’s now hookup our sender and receiver along a differential signal. If these spikes are strong enough, the receiver will treat these signals as digital inputs, even though they’re not supposed to be there in the first place! What happens? Since we’re not prepared to receive these signals, it’s undefined, and anything goes! Our encoders will read random numbers, steppers will take bonus steps, buttons will read: pressed, rockets will blast off, satellites will fall out of orbit, and we are so fired. From Faraday’s laws, a changing magnetic field from the motor will induce a voltage along these wires, which we’ll pick up as a voltage spike. Now, suppose we add some electromagnetic interference (EMI) by introducing a nearby motor and turning it on. Let’s assume the sender sends a digital output (logic 0 or logic 1), and the receiver expects to receive a digital input (logic 0 or logic 1). Just imagine a lengthy hookup wire between breadboards. To get the conversation started, we run a single-ended signal over a long cable from one device to another. Suppose we have two devices that want to communicate over a single wire. Let’s take a moment for a brief “differential-signals-101” lecture. They’re simple, fairly standardized, and just too elegant to ignore. From all of the choices we covered, I picked differential signals. There’s a host of ways to make I☬’s communication lines more noise resistant. What’s so Schnazzy about Differential Signals? Behold: an IMU Noodle is born! Grab yourself a cup of coffee and join me as I arm you with the nuts and bolts of DI☬ so that you too can run I☬ over long cables like a boss. Specifically, I have put together a differential I☬ (DI☬) setup with the PCA9615 to talk to a string of Bosch IMUs. This month I plucked my favorite solution from the bunch and gave it a spin. For prototyping? Yes! But for a bulletproof production environment, this practice just won’t make the cut. * You can add an analog switch multiplexer like the MAX4618 which is still available in DIP package.A few weeks back, we talked about the no-nos of running I☬ over long wires. * You can use a soft I2C controller on any GPIO. * You may be able to connect both I2C devices to the same port if they can have different I2C addresses.
#I2C VS UART PERFORMANCE CODE#
In i2c_api.c and serial_api.c of LPC4088 target p19,p20 (I2C0) or p17,p18(UART3) are listed in Pinmap structure, but I would like to know if they work out of the box, as I don't understand the code completely yet.
#I2C VS UART PERFORMANCE SERIAL#
The resistor used in HDK UART is just a safety measure in case I accidentally use a printf() ?Īnyway I would prefer to use solution 2) if possible, because that leaves xbee and virtual serial port available.
#I2C VS UART PERFORMANCE SOFTWARE#
As for a software solution, I think it may be easier to use the three methods I mentioned. Also, the uC will be in very tight place, so I would avoid external devices. I should have clarified that I want 2 I2Cs because of conflicting addresses. Their example interface design schematic suggests adding a series resistor if you try to use the HDK UART.
#I2C VS UART PERFORMANCE HOW TO#
UART2 at the XBee connector may be the simplest solution, but the UART how to says you can override the HDK UART.
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