The Raspberry Pi Project has announced the availability of the next generation Raspberry Pi Zero W board, which combines compact size with Bluetooth and Wi-Fi support. The new Raspberry Pi Zero 2 W model is made in the same miniature form factor (65 x 30 x 5 mm), i.e. about half the size of a regular Raspberry Pi. So far, sales have begun only in the UK, the European Union, the USA, Canada and Hong Kong, deliveries to other countries will open as the wireless module passes certification. The Raspberry Pi Zero 2 W is priced at $15 (for comparison, Raspberry Pi Zero W is $10 and Raspberry Pi Zero is $5, cheaper boards will continue to be made).
The key difference of the new Raspberry Pi Zero model is the transition to the use of the Broadcom BCM2710A1 SoC, close to that used in the Raspberry Pi 3 boards (in the previous generation of Zero boards, the Broadcom BCM2835 SoC was supplied, as in the first Raspberry Pi). Unlike the Raspberry Pi 3, the processor frequency has been reduced from 1.4GHz to 1GHz to reduce power consumption. Judging by the multi-threaded sysbench test, the SoC update allowed to increase the performance of the board by 5 times (the new SoC uses a quad-core 64-bit Arm Cortex-A53 CPU instead of a single-core 32-bit ARM11 ARM1176JZF-S).
As in the previous edition, the Raspberry Pi Zero 2 W offers 512MB of RAM, a Mini-HDMI port, two Micro-USB ports (USB 2.0 with OTG and a port for power supply), a microSD slot, a 40-pin GPIO header (not soldered), composite video and camera outputs (CSI-2). The board is equipped with a wireless chip that supports Wi-Fi 802.11 b/g/n (2.4GHz), Bluetooth 4.2, and Bluetooth Low Energy (BLE). To pass the FCC certification and protect against external interference, the wireless chip in the new board is covered with a metal casing.
The SoC-integrated GPU supports OpenGL ES 1.1 and 2.0, and provides tools to accelerate H.264 and MPEG-4 video decoding with 1080p30 quality, as well as H.264 encoding, which expands the board's use by various multimedia devices and systems for smart home. Unfortunately, the RAM size is limited to 512 MB and cannot be increased due to the physical limitations of the board size. Delivery of 1GB of RAM would require the use of a complicated multi-layer design, which the developers are not yet ready to implement.
The main design challenge for the Raspberry Pi Zero 2 W board was LPDDR2 SDRAM placement. In the first generation of the board, the memory was placed in an additional layer above the SoC chip, implemented using PoP (package-on-package) technology, but this technique could not be implemented in the new Broadcom chips due to the increase in the size of the SoC. To solve this problem, together with Broadcom, a special version of the chip was developed, in which the memory was integrated into the SoC.
Another problem was the increase in heat dissipation due to the use of a more powerful processor. The problem was solved by adding thick copper layers to the board to remove and dissipate heat from the processor. The weight of the board increased noticeably because of this, but the reception was recognized as successful and it turned out to be enough to avoid overheating when performing an unlimited LINPACK linear algebra stress test at an ambient temperature of 20 degrees.
Of the competing devices, the closest thing to the Raspberry Pi Zero 2 W is China's Orange Pi Zero Plus2, which measures 46x48mm and ships for $35 with 512MB of RAM and an Allwinner H3 chip. The Orange Pi Zero Plus2 board is equipped with 8 GB EMMC Flash, has a full HDMI port, a TF Card slot, USB OTG, as well as pins for connecting a microphone, an infrared receiver (IR) and two additional USB ports. The board is equipped with a quad-core Allwinner H5 (Cortex-A53) processor with Mali Mali450 GPU or Allwinner H3 (Cortex-A7) with Mali400MP2 GPU. Instead of the 40-pin GPIO, there is a reduced 26-pin header that is compatible with the Raspberry Pi B+. A less powerful Orange Pi Zero 2 board is also available, but it comes with 1 GB of RAM and an Ethernet port in addition to Wi-Fi.
Source: opennet.ru