The ESP-01 Wi-Fi module is one of the most popular ESP8266-based microcontroller board. It is very inexpensive and widely available. If you are new with ESP-01 modules, or are contemplating on buying one, you are lucky for visiting this page. We have here all the necessary information on the difference between ESP-01 and ESP-01S Wi-Fi modules.

The ESP-01 module and the ESP-01S module are functionally the same. However, knowing the difference between the two is very important because it can affect how you wire them to external circuits. Also, the boards have different current consumption owing to their difference in the number of onboard LEDs.

ESP-01S is a Newer Version

First off, the ESP-01 module was the original version that was popularized almost a decade ago. The ESP-01S is the newer version. At the time of this writing, circa 2023, the original ESP-01 module is still widely available. Most online stores would allow you to choose between an ESP-01 or an ESP-01S. But some stores may sell you an ESP-01 for an ESP-01S, or vice versa.

Difference in Physical Appearance

At first glance, the two modules look the same. However, a close examination of the boards will show the difference in the number of LEDs (Light Emitting Diodes). Please see Figure 2 below. In the original ESP-01, there are two (2) small LEDs. On the other hand, the ESP-01S has a single, bigger LED.

The difference becomes more apparent when you supply power to the boards. The ESP-01 board will have a red LED light turned on indicating the presence of power. On the ESP-01S board, you will only see a blue LED flash for a while when the power is applied.

The Blue LED Wiring Difference Between ESP-01 and ESP-01S

Although both boards have a blue serial-activity LED, the blue LEDs are wired differently. See Figure 3. In the ESP-01 board, the blue LED is connected on the VCC and the TX pins, while on the ESP-01S, it is connected on the VCC and the GPIO2 pins. On both boards, a 2.2K ohms resistor is used in series with the blue LED as a current limiter.

Pull-up Resistors on ESP-01S

Another difference between ESP-01 and ESP-01S is the presence of three (3) pull-up resistors on the ESP-01S module. Pull-up resistors are used to provide a logic HIGH signal to a circuit. As shown on the right side of Figure 3 above, three (3) 12K-ohm resistors are connected from the VCC to the RESET, GPIO0, and CH_PD pins on the ESP-01S board.

Prior to the availability of the ESP-01S module, a popular ESP-01 wiring scheme for adding a reset switch and a programming switch is shown below in Figure 4. First of all, in order to power up the ESP-01 board, you need to pull up the CH_PD (Chip Enable/Power Down) pin. Next, you connect the RESET pin to the VCC because you do not want the RESET pin hanging and be vulnerable to noise causing unexpected resets. And third, pulling up the GPIO0 pin to VCC will automatically run the program or sketch loaded on the ESP-01 module after a power up or a reset.

On the newer ESP-01S module, the circuit shown above will be a lot more simple. There is no need to externally supply the three (3) pull-up resistors. See Figure 5.

Summary on Difference Between ESP-01 and ESP-01S

The ESP-01 and the ESP-01S Wi-Fi modules are functionally the same. The ESP-01S module is a newer version of the original ESP-01 module. The ESP-01 module has a red power indicator LED that is absent on the ESP-01S. Both modules have a blue LED that indicates serial activity. However, the blue LED is wired differently on each module’s version. And finally, the ESP-01S module has three (3) on board pull-up resistors that are missing on an ESP-01 module.

Related Articles

How to Program ESP-01 with Arduino IDE
How to Set up Arduino IDE for ESP8266 Programming
How to Test an ESP-01 ESP8266 Module
How to Control ESP-01 thru a Router
How to Control ESP-01 Without a Router
ESP-01 with RTC and LCD Display
How to Save and Restore ESP8266 and ESP32 Firmware
NodeMCU V3 ESP8266 Pinout and Configuration
How to Test a NodeMCU V3 ESP8266 Dev Board
How to Use AT-09 BLE with Arduino and Smartphone

References on Difference Between ESP-01 and ESP-01S

ESP8266 on Wikipedia
ESP8266 Boot Process

The post Difference Between ESP-01 and ESP-01S appeared first on CyberBlogSpot.

To use an Arduino board as an ISP programmer, simply upload the Arduino IDE example sketch named “ArduinoISP”. Next, connect the SPI pins of the Arduino board to the MCU chip or MCU board to be programmed. Then, you can start using the Arduino board as an ISP programmer.

To illustrate the steps for the procedure, first, I will make an Arduino Nano board into an ISP programmer. Then, I will show how to upload sketches and burn bootloaders to a Digispark ATtiny85 development board.

Step by Step Guide on How to Use Arduino as ISP Programmer

STEP 1 – Connect your Arduino board to your computer’s USB port.

Connect the Arduino board of your choice to your programming computer hosting the Arduino IDE. In the next several steps, we will upload the ArduinoISP sketch to the board to make it an ISP programmer.

STEP 2 – Open your Arduino IDE and open the ArduinoISP sketch.

Open your Arduino IDE. If you are a beginner and you have not yet installed the Arduino IDE, please see How to Install Arduino IDE on Windows 10. On the Main menu, select File/Examples/11.ArduinoISP/ArduinoISP.

You should see the screen shown below after clicking on the ArduinoISP on the Built-in Examples menu.

STEP 3 – Choose the name of your Arduino board from the Board Manager’s list.

Go to Tools/Board/Arduino AVR Boards and select the type of Arduino board you are using. As shown in the screenshot below, I chose Arduino Nano for my Arduino board.

STEP 4 – Set the proper COM serial port for your board.

On the Tools menu, select Port. Then select from the serial ports list the appropriate port for your Arduino board.

STEP 5 – Click the Upload button.

As a final step for uploading the ArduinoISP sketch to the Arduino board, click on the Upload button.

When you see the message “Done uploading”, congratulations!!! You now have a full-pledged ISP programmer.

In the following steps, we are going to show how to use the Arduino board acting as an ISP programmer to:

• Program or upload a sketch to a Digispark ATtiny85 board
• Burn an Optiboot bootloader
• Burn a Micronucleus bootloader

STEP 6 – Connect the ISP programmer (the Arduino board) to the Digispark ATtiny85 development board.

Like in any other ISP programmers, including the popular USBtinyISP and USBasp programmers, we use six (6) terminals of the ISP programmer to connect to the device to be programmed. These terminals are:

• MOSI
• MISO
• SCLK
• RESET
• VCC
• GND

On the Arduino board acting as an ISP programmer, the corresponding terminals are as follow:

• D11 (MOSI) —> MOSI
• D12 (MISO) —> MISO
• D13 (SCLK) —> SCLK
• D10 (SS) —> RESET
• 5V —> VCC
• GND —> GND

Now, based on the foregoing discussion, we can connect the Arduino board to the Digispark ATtiny85 board using the following terminals:

Arduino Board —> Digispark ATtiny85 Board
D11 (MOSI) —> PB0(MOSI)
D12 (MISO) —> PB1(MISO)
D13 (SCLK) —> PB2(SCLK)
D10 (SS) —> PB5(RESET)
5V —> 5V
GND —> GND

For reference purposes, the Digispark ATtiny85 development board pinout is shown below. For more information on Digispark ATtiny85, you may consult the Digispark ATtiny85 Pinout and Configuration.

Shown below is the Fritzing breadboard diagram for connecting the Arduino Nano board to the Digispark ATtiny85 board.

How to connect the Arduino Nano board to the Digispark ATtiny85 board illustrated by an old-school schematic diagram.

After connecting the Arduino board to the Digispark ATtiny85 board, we are now ready to test drive the Arduino board as an ISP programmer.

Since we are going to work with the Digispark ATtiny85 board, you must have the board core ATTinyCore by Spence Konde installed on your Arduino IDE. If you do not have the ATTinyCore installed yet, see the article How to Install ATTinyCore on Arduino IDE.

STEP 7 – Copy and Paste the Blink Program.

Going back to the Arduino IDE, create a new sketch and then copy and paste the Blink program sketch shown below.

/*
www.cyberblogspot.com
07Jan2022  
*/

#define LED_BUILTIN 1  //PB1 for Model A
                       //PB0 for Model B

void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);                       // wait for a second
}

STEP 8 – Change the board from Arduino board to Digispark ATtiny85 board.

Go to Tools/Board/ATTinyCore and select ATtiny25/45/85 (No bootloader). Take note that we are using the “No bootloader” option and NOT the “Micronucleus/Digispark” option. This is because we are going to upload the Blink sketch via an ISP programmer (the Arduino board) and not thru the Digispark’s USB port.

STEP 9 – Select the proper COM port.

Go to Tools/Port and choose the correct COM port from the ports list.

STEP 10 – Select the programmer type.

On the Tools/Programmer menu, select Arduino as ISP as the programmer type.

STEP 11 – Upload the Blink program.

Upload the Blink program by clicking on the Upload button.

When you see the message saying that the upload is done, your Digispark ATtiny85 board should start blinking the built-in LED.

How to Burn Bootloader on Digispark ATtiny85 Using Arduino as ISP Programmer

Burn Optiboot Bootloader

STEP 1 – Select ATtiny45/85 (Optiboot) from the ATtinyCore list.

STEP 2 – Verify that the proper COM port is selected.

STEP 3 – Make sure that the programmer selected is “Arduino as ISP”.

STEP 4 – Click “Burn bootloader” to start the burning process.

Burn Micronucleus Bootloader

To burn the Micronucleus bootloader onto the Digispark ATtiny85 board using the Arduino as ISP programmer, follow the steps above for burning the Optiboot bootloader. However, instead of selecting ATtiny45/85 (Optiboot), select ATtiny85 (Micronucleus / Digispark) from the ATtinyCore list of supported devices.

References on How to Use Arduino as ISP Programmer

In-System Programming (ISP)
How to Install ATTinyCore on Arduino IDE
How to Program ATtiny85 with Arduino IDE
Digispark ATtiny85 Pinout and Configuration
How to Program Digispark ATtiny85 Board with Arduino IDE
Digispark USB Device Not Recognized
How to Use AT-09 BLE with Arduino and Smartphone

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